Qa engineer requiredpráce

Hledáš možnost zapojit se do dynamického prostředí plného inovací a rychlého rozvoje? Pokud ano, připoj se k nám. Jsme tým odhodlaných a nadšených lidí poskytující fulfillmentové služby našim zákazníkům. Navrhujeme a poskytuje klientům ucelená řešení pro jejich business. Postaráme se o outsourcing logistiky, expanzi do zahraničí, napojení na marketplaces, optimalizaci skladových zásob i zlepšení procesů. Jako náš nový kolega/kolegyně, který se připojí k našemu týmu budeš mít klíčovou roli při návrhu, implementac...

3d design & Mould design by “pro engineer”

Only candidates with experience in software development and software testing can apply for this job. Crowdville is an online testing community with over 100,000 users in Italy, UK and Portugal...This is a work from home job and you must live in Hungary or the Czech Republic. Hourly paid. No more than 8 hours of tests spread over 1 month. Job description: -Tasks will include user testing and bug reporting: documentation of process, tests, results and analysis. Job Requirements: - Experience in testing or software development. - Proficiency in English. - Experience in software testing/QA/Software development - Live in Hungary or Czech Republic Do you want to learn more about us? Check out: Crowdtesting Platform: Managed by:

I need 3D scanned models in any of the fol...Autodesk Inventor Files (*.ipt, *.iam) CATIA V5 Files (*.CATProduct, *.CATPart) DXF Files (*.dxf) FBX (*.fbx) IGES (*ige, *iges, *igs) NX (*prt) OBJ (*.obj) Parasolid Binary Files (*.x_b) Parasolid Text Files (*.x_t) Pro/ENGINEER and Creo Parametric Files (*.asm, *.prt) Pro/ENGINEER Granite Files (*.g) Pro/ENGINEER Neutral Files(*.neu) Rhino Files (*.3dm) SAT/SMT Files (*.sab, *.sat, *.smb, *.smt) SolidWorks Files (*.prt, *.asm, *.sldprt, *.sldasm) STEP Files (*.ste, *.step, *.stp) STL Files (*.stl)​ SketchUp Files (*.skp) 3D scanning models of the following models required Models Hero Splendor Honda Activa Hero HF Deluxe Honda CB Shine Bajaj Pulsar Hero Glamour TVS XL Moped Hero Passion TVS Jupiter Bajaj Platina Ro...

need a boonex dolphin pro trainer

PRO-E CAD WORK

We are looking for an experienced electrical engineer to assist us in solve this issue an Electrical Single Line Diagram (SLD) for a Photovoltaic field with a capacity of 2.8 MW. "The single-line diagram lacks all the part related to the MT side protection systems (DG+SPG, DDI+SPI, backup system, etc.) as per CEI 0-16 standard." additionally they tell me this: Additionally, considering that the distribution network voltage in Umbria is at 20 kV, there is a transformer power limit of 2000 kVA with Vcc at 6%. In fact, CEI 0-16 standard states that 'The user must not install transformer sections exceeding this power threshold; except for cases of larger sizes provided that, due to the impedances between the connection point and the LV side of the transformers (MT user l...

I am working on React JS with Javascript Development Project. I need someone to Support me for this Project atleast 4 to 5 hours Per day. Project will Exist more than 2 years. I need support through Remotely(zoom). I am looking for Good Exper...than 2 years. I need support through Remotely(zoom). I am looking for Good Experienced(4+ years) Person as a Frontend Developer, Who can work on the tasks Quickly. I am looking for Long term relationship. After this Project Completed means, we will give immediately another support project. I will Give you the Sample Task for 1 Hour, If you Completed ON TIME means we will give you the Project. Required Skills : React JS, HTML, CSS, Javascript, Cypress Test Cases(Mandatory), SQL Basics Language Speaking Person : English Note: I will pay on ho...

I'm looking for a skilled audio engineer to help set up my small studio for music production. Key Requirements: - Setting up and optimizing my existing microphones and mixing console - Designing the studio to enhance sound quality in a small space The main goal of the studio is music production, so the engineer should be experienced and knowledgeable in this specific area. The studio will be used primarily for music production, so it's essential to optimize the setup for this purpose. Ideal skills & experience: - Proven experience in setting up studios for music production - Proficiency in working with small spaces - Understanding of sound engineering principles in music production.

I need an expert to integrate a court booking plugin it into my existing wordpress website, implementing several essential functionalities. Key Requirements: - Enable online booking on our website: - Email notifications: Skilled in setting up automated emails tied to successful booking, cancellations, or changes in booking status. - SMS Gateway - Payment Gateway I already have tried paid plugin but seems to be taking so much time so I need an expert to get this done quickly. Ideal freelancers should have a proven history of plugin integration, working knowledge of appointe booking software, and a deep understanding of automated system notifications. Familiarity with online booking systems and real-time calendar synchronization is highly desirable for this project.

I'm in need of an experienced industrial designer or mechanical engineer who can help me create a new in-row hoe design. Key Details: - **Purpose**: The in-row hoe will be used primarily for weeding. - **Environment**: The hoe will primarily be used in large commercial farms. Prior experience in agricultural equipment design or similar projects is a plus. I'm looking for someone who can: - Understand the specific needs of the agricultural industry - Design a product that is both efficient and durable - Incorporate any necessary features for maneuverability, given the large scale of use Your expertise and creativity in this field will be crucial to the success of the project. If you're up for the challenge, please send me your credentials and any relevan...

URGENTT PROJECT. The project would be to design and build a PCB device and 3D Printable enclosure that supplies power via POE (power over Ethernet) to equipment and can accept a standard construction equipment battery from a manufacturer such as Dewalt, Ryobi, etc. to provide the power to the attached device. There should be 2 Ethernet ports (an incoming and outgoing ethernet port) supporting 5Gbps and the power draw will be selectable via switch or button. The power will need to conform to the standards for 802.3af (POE), 802.3at (POE+), and 802.3bt (POE++) and include a power meter that shows the amount of battery power remaining. A USB-C port should also be included. The enclosure should be 3D printable.

I'm seeking a skilled web developer to UPLIFT an eCommerce store via SQUARESPACE for selling physical products. This store will sell customizable jewelry. The website is already created but we need to: 1. Update the style/colour/formatting and design of the front end. I am not happy with my colour schemes and font choice. Please help me improve the design. 2. Optimise my website for mobile 3. Improve functionality, spacing, and formatting using code. There is ~25 design and functionality changes that need to be changed e.g. Add pop up at checkout for ring size guide. Logo, media, text etc will all be provided.

Following are the requirements of task to be fulfilled. 1- Task is to visit the Gottingen physically and Take 5 to 6 geotagged photos of with name board captured and from outside the building. 2- Get the verification form filled, signed and stamped by the HR and also stamp the certificate. 3- Get the details of verifier, Name, Designation, Department and Contact. 4- In case of refusal to fill form, take the written refusal with stamp or sign as a proof. 5- If companydoes not found on given address than take the 7 to 8 geotagged photos of exact address with right left name boards photos and make a small few seconds video of address . Also get the details of any nearby business ( Name of person, Business name and Contact

I'm seeking a mechanical design engineer with a background in material selection, mechanical system design, and safety and reliability analysis. The project revolves around designing a screw conveyor. This includes: - A comprehensive understanding and execution of both aspects of machine design mentioned above, coupled with proficiency in creating a Bill of Materials (BOM) that also includes an estimate. - The screw conveyor design must be medium-sized with a capacity between 1-10 tons/hour. Please note, experience in conveyor system design is vital. Eligible freelancers should demonstrate their ability to design reliable and efficient mechanisms that prioritize safety. A strong track record in similar projects will significantly increase your chances of being selected.

As a senior web engineer, I need assistance with an older React project that is currently on hold. The main goal for resuming this project is to modernize the application's user interface and optimize its performance. Key Requirements: - Experience with old React projects and updating them to the latest React version - Proficiency in improving scalability and performance in React applications - Ability to modernize a user interface of an existing React project Your contribution will be crucial in getting this project back on track and making it more efficient and user-friendly.

I'm in need of a skilled structural engineer specializing in residential buildings, to calculate fastening requirements for 2 piece clay roofing tile based on /the information in the TRI manual, size of US Clay 2 piece tile. 130 mph wind speed class c requirements& local building code Key Requirements: - Expertise in residential structural engineering - Prior experience with roofing tile installations - Ability to asses fastening requirements/options based on the information in the TRI manual, size of US Clay 2 piece tile. 130 mph wind speed class c requirements& local building code. Please only apply if you have experience with similar projects and can provide evidence of successful completion.

I am looking for some freelance engineers to undertake drainage design work for projects based in the U.K (England principally). This work can...be done remotely. This would involve the use of Causeway Flow+ design software (which I can provide some training with) and a CAD package. I am a freelance flood risk and drainage engineer based in England and sometimes have more work than I can handle. I am looking for some contacts with whom I can share work when required. Any experience of working in the U.K would be beneficial (but not essential). The work typically involves designing outline and detailed surface water (stormwater) drainage systems for new developments (residential, commercial, industrial). Sometimes foul water systems are required too. Thank...

I'm in search of a highly skilled server engineer who understands VPS and email servers. The current system I have in place with Contabo and Zimbra is unreliable and requires daily restarts, clearly, this is far from ideal. Your task will be to either create a stable setup with the current tools, or propose and implement a new, more reliable solution. Key Aspects: - High uptime: The system should rarely, if ever, require manual restarts. - Scalability: While the exact number of email accounts needed is not yet determined, the setup should be highly scalable to accommodate growth. Support: - Although no specific level of support was specified, basic troubleshooting is expected as part of your proposal. Higher level support options can be discussed based on your recommendat...

Seeking an experienced QA tester based in Thailand to perform functionality testing on our cross-platform mobile app. This is final testing before launch and URGENT as we launch ASAP. You will perform tests following the test cases provided by us. Having a solid understanding in app functionality testing is crucial. I am only accepting bids from professionals who can work in daylight hours and are based in Thailand. Please share any relevant experience and success in similar projects. We seek to hire TODAY, May 3, 2024 if possible and seek to start you as soon as possible (today if possible). Essential Skills & Requirements: - Cross-platform mobile app testing (Android, iOS) - Excellent understanding of functionality testing - Capacity to strictly follow provided ...

Typical Functions: Data Architecture: Leverage your 5+ years of experience in designing and optimizing database solutions. You’ll work closely with stakeholders to create a robust data architecture that seamlessly integrates various data sources. Programming Languages: Demonstrate proficiency in Java and C#. Your code is not just functional but elegant. Team Leadership: As a seasoned engineer, you’ll mentor junior team members, foster collaboration, and drive technical excellence. Cloud Solutions: Familiarity with Azure or AWS is essential. You’ll architect, deploy, and manage cloud-based solutions. Data Import Strategy: Devise a robust strategy for importing data efficiently, ensuring data quality, and maintaining performance. Collaboration: Work closely with cro...

I'm organizing a live performance for two latin bands in an intimate venue in Northcote. The performance will be on May 11 from 4-8pm and we are expecting an audience of 50-200 people. I'm looking for a skilled and experienced sound engineer who can create a balanced sound experience for our audience. Our venue is equipped with a PA system and microphones. The sound engineer will be responsible for using this equipment to achieve optimal sound quality for the bands' live performance. Skills/Experience required: - Demonstrable experience in live sound mixing, ideally with latin music - Ability to use a PA system and microphones effectively - Understanding of the unique acoustic needs of a live music venue - Availability on May 11 from 4-8pm.

As the head of operations for a polymer company, I urgently need the expertise of a skilled chemical engineer who has a sound understanding of unsaturated polymers, MEKP, and cobalt accelerator. Our main objectives for this project are: • Research and development specifically relevant to unsaturated polymers • Achieving an optimal medium cure time • Minimizing waste through precise usages of chemicals at specific temperatures Our goal is to achieve the best cure time and minimize waste. However, we’re facing challenges during the winter and rainy seasons, typically when the temperature drops to around 5 degrees Celsius and the conditions become humid. During these periods, we’ve observed that the reaction does not start as expected. We’re unsur...

I'm in need of a Thai-English bilingual assistant to help me contact Thai Companies (I will provide the leads). This assistant will need to help connect me with a purchasing officer or engineer or manager within the company for me to introduce my company to. My company specializes in offering Engine spare parts for Marine Diesel Engines (Main Engines and Auxiliary Engines). So all of the companies this assistant will be required to contact are related to Marine (ocean) Shipping Lines, Ferries, Ship Owners or Ship Repair Yards. Key Role Responsibilities: - Establish initial contact with companies in Ferry, Marine Transport, Fishing Companies, Ship Repair Shipyards, Ship Owners - Offer our company's services of providing Engine (Main and Auxiliary) Spares for the pur...

I need Satta matka android application with admin panel .

I'm in need of an experienced structural engineer to aid in the finalization of construction documentation for a house located on the Gold Coast in Australia. Key Requirements: - The project is currently in the construction documentation phase, so I need support for this particular phase. - The primary focus of the engineering support is on the load-bearing capacity of the structure. - The house's location necessitates that the design is able to support the region's specific conditions, including its wind loads. Ideal Skills and Experience: - Proficiency in structural engineering, particularly in residential projects. - Prior experience with construction documentation for buildings. - Expertise in load-bearing analysis, and ideally experience with wind load analys...

I require an experienced drafter to create comprehensive workshop fabrication drawings for structural steel components (specifically beams and columns). These drawings need to be in PDF format. Whi...beams and columns). These drawings need to be in PDF format. While no specific standard or code was requested by me, it would be beneficial for potential candidates to have a strong knowledge of structural steel design codes. Proficiency in tekla, advance steel or similar software is a minimum requirement for this project. A set of drawings for review will be required prior to the release of the milestone payment, once the engineer approves the drawings for fabrication the payment will be processed via freelancer. I have architectural and engineering plans reflecting all critic...

Greetings We have the architect design drawings completed, looking for a structural design for one floor building, using stabilized compressed earth bricks, for the ceiling, we are looking to adopt Catalans vaulted brick” and : barrel-vaulted”. Furthermore, we required the structure design to be according to an International reference code, and to be stamped from a registered architect in USA or Europe, please. Our preferred is, an experienced engineer skilled in adobe construction to help with my residential build project. We're at the initial planning stages, and I have a design already in mind. The ideal candidate would have: - Expertise in adobe building structure - Familiarity with residential construction - Ability to translate design idea...

I'm looking for a Control Engineer with proficiency in Matlab to help with a project focused on modeling and simulation. The primary goal of this project is to optimize the performance of a system. Key requirements and responsibilities: - Expertise in modeling and simulation within Matlab - Background in control engineering - Ability to analyze and understand system behavior - Create and implement strategies to enhance system performance - Strong communication skills to collaborate on project goals and updates While the type of system to be optimized hasn't been specified by the client, experience with mechanical, electrical, or hybrid systems would be a plus. Your expertise will be crucial in ensuring the successful optimization of the system.

As the owner of a diverse range of products, I need a skilled copywriter to create engaging and informative product descriptions. Following in-depth knowledge and understanding of my product line will be necessary, with the intent of showcasing their distinct features and benefits. - I need assistance in creating an appealing copy that will captively describe each product whilst also promoting their unique qualities and advantages. - To gain a comprehensive understanding of the products, I will provide detailed product specifications, competitor product descriptions, and user testimonials. - Expertise in creating compelling and captivating copy, coupled with an understanding of selling strategies and product marketing is ideal. - A keen eye for detail and strong research skills are nec...

I'm seeking an Electrical Solar Engineer to assist in a new solar project. Key Responsibilities: - Provide expert advice on solar systems and their installation - Assess and consult on the most suitable solar system size for the project - Ensure compliance with all relevant regulations and standards Ideal Candidate: - Proven experience in solar engineering - In-depth knowledge of solar power systems - Strong understanding of electrical engineering - Ability to work with a team to deliver timely and cost-effective solutions.

I am seeking a talented and experienced Mobile Application developer familiar with the Multi-platform App User Interface (MAUI) framework to create a data display mobile application. The specification of the application remains open, as I am unsure about the need for integration with external APIs or databases. Skills I am looking for: * Proficiency in MAUI development * Experience in creating apps for multiple platforms * Good understanding of API and database integrations * Ability to provide technical advice and recommendations Your main task will be establishing the foundation of the app considering future functionalities might be added. Your insights and expertise are key, as the specifics beyond data display and the potential requirement for external integrations are still to be d...

Hi, i Will Help you In setting up Advance Tracking and Reporting for your website. please accept the quote request and lets discuss further. Thanks

I need an experienced optical engineer to help design an imaging system primarily intended for lithography. The tasks that I expect the freelancer to perform include: I am building a projector to expose a photosensitive-coated target with UV light. This projector must have an adjustable image output that varies from 0.1 reduction [image source to target image] down to about 0.02 reduction. At all image reduction settings, the focus must be adjustable. The input image will vary from about 5mm to 1mm, and the output image will be from 1.5mm to 0.25mm. The light source will be LED, outputting 50 watts of mid-UV light. The output of this gig shall be a drawing/sketch of the relative positions of each optical element in relation to the light source [UV light], the source image/film, ...

I'm in need of a talented DevOps engineer, proficient in AWS and GitHub Actions, to assist with an array of DevOps tasks. Key Tasks: - Deploying web applications - Infrastructure automation - Continuous integration and deployment (CI/CD) The applications are built using Java, requiring deep expertise in this language for effective collaboration. To succeed in this job, a solid understanding of web applications, coupled with extensive experience using AWS and GitHub Actions, is critical. Automation skills are also vital. Join us and help make our Java web application deployment seamless and efficient!

I'm in need of a DevOps Engineer who can assist me in containerizing a Docker application. I'm interested in your expertise in managing containerized applications, ensuring they can scale effectively, and maintaining a high level of security. Key Tasks: - Containerization: Implementing the best containerization platform based on your experience. - Scalability: Designing a solution that can easily scale and handle increased loads. - Security: Ensuring network isolation, access control, and secure image signing are properly implemented. Ideal candidates should have: - Strong experience with containerization platforms like Docker Swarm, Kubernetes, or Apache Mesos. - Proven expertise in designing and maintaining scalable architectures. - A comprehensive understanding of sec...

Change the payment gateway "cryptomus" to stripe. After that. Compile the code to obtain the apk version and an .aab version that will be used in the Google Play Store. In turn, upload the updated code to the app server. Send me the updated source code as well. The app is made on react Native, and the backend is Python. All the API's are made on Python.

I'm looking for a skilled photo editor to conduct numerous touch-ups on a specific image. Some of the tasks include: - Logo Removal: There are logos present on the chest and sleeve of the subject's shirt that need to be completely removed. - Skin Retouch: Some minor adjustments to be made to the subject's skin to ensure a cleaner look. - Hair Correction: I would like some fly aways in the hair to be retouched out of the image. The perfect candidate for this project needs a strong understanding of photo editing software, a keen attention to detail, and previous experience in similar projects. Demonstrating an ability to work with hair and skin retouching in a photo editing software will be a big plus. This project could potentially lead to more work in the future if done we...

We are seeking a skilled and motivated Link Building Specialist to join our team. As a Link Building Specialist, you will be responsible for acquiring high-quality backlinks to improve our website's search engine ranking and drive organic traffic. You will employ various strategies to identify and secure link-building opportunities while adhering to best practices and ethical guidelines.

Responsibilities: Assist with administrative tasks such as filing, data entry, and scheduling. Provide support to various departments as needed. Assist with research projects and presentations.

I'm in need of an experienced 2D animator to create traditional hand-drawn cat and animal based animations for social media / website content. Key Requirements: - The animation style should be traditional hand-drawn based on a characters already designed. - The primary use of the animation will be for social media and website content. The deliverables should include: - Individual scenes/files for potential future use. - A complete video that can be directly posted on social media and website. (also YouTube) Ideal Candidate: - Proven experience in creating traditional hand-drawn animations based on concepts provided. - Previous work in creating content for social media and brand promo focused works. - Able to deliver animations in both scene and video formats. Please provide sampl...

I'm in need of a professional engineer who can help me assess the wind load on a shelter structure in a coastal area. The ultimate goal is to ensure the structural integrity and safety of the Industrial Analyzer Shelter that I'm planning to construct. Key aspects of the project include: - Wind Load Calculation: The engineer should be capable of conducting thorough wind calculations, considering the specific environmental factors associated with a coastal setting. - Structural Integrity: The aim is to guarantee that the shelter design can withstand the maximum wind conditions expected in the location, maintaining its integrity and safety over time. Ideal Skills and Experience: - Engineering Background: The ideal candidate should have a strong background in structur...

Looking for a motivated and enthusiastic Social Pages Management Intern to join our team. In this role, you will have the opportunity to gain hands-on experience in managing our social media presence across various platforms, including but not limited to Facebook, Instagram, Twitter, and LinkedIn. Responsibilities: Create and curate engaging content for our social media platforms. Schedule and publish posts using social media management tools. Monitor social media channels for comments, messages, and mentions, and respond promptly. Assist in developing and implementing social media strategies to increase brand awareness and engagement. Track and analyze social media performance metrics and prepare reports for management. Stay updated on industry trends and best practices in social media ...

I'm in need of an Excel expert who can assist me with a project that involves data analysis, financial calculation, and advanced formula and functions. This project involves working on a single Excel file with the main goal of improving data organization. This requires a hands-on approach, strong problem-solving skills, and a keen eye for detail. Skills/Experience Needed: - Advanced Excel proficiency - Strong background in data analysis and financial modeling - Experience in creating complex formulas and functions - Excellent organizational and problem-solving skills. Your work will be instrumental in streamlining our data handling processes and make them more efficient. Please provide examples of similar projects you've worked on in the past.

I'm in need of a proficient video editor capable of bringing life to my variety of video content which includes short videos, long videos and promotional content. Key Responsibilities: - Skillfully editing all video types within a 1-2 day turnaround period. - Adding motion graphics to enhance the visual appeal. - Creating and integrating subtitles for imp...- Creating and integrating subtitles for improved understanding. - Incorporating voiceover to make the content engaging and dynamic. Ideal Skills: - Proven experience in video editing. - Proficiency in motion graphics and subtitles creation. - Voiceover addition experience. - Capability to work within tight schedules and deliver quality work. If you are quick, creative, and equipped with the required skills, I'd lo...

I am looking for an AI engineer who has experience in lipsync model. You should create a 20 or 30 seconds of video with one image and not only mouth but also the shoulders and hands are also expected to move naturally. If you use opensource model or your previous model, it's okay. Just if the pixel of generated model seems like the one from EMO(Alibaba). Some requirements: - Under 4 seconds of latency for a 30-second lipsync - 480p quality or greater in it's entirety - EMO/HeyGen level quality - No bugs - Must be optimized/quantized - Roughly 7 days Ideal candidate: - Has a deep understanding of Lipsync AI technology. - Has strong experience with Machine learning

I am seeking an AI engineer with a strong background in developing lipsync models, specifically image-to-video. - Skill Required: Deep understanding of lipsync technology, focusing on image-to-video conversions. - The freelancer must demonstrate their previous work experience, highlighting projects where they successfully completed image-to-video lipsync model development. - The emphasis should be on their expertise with lipsync models over general AI experience. Interested applicants, please apply with detailed examples of past work, especially those related to lipsync models.

I'm looking for a talented video editor who can enhance my YouTube content. Key requirements include: - Expertise in editing YouTube videos specifically with a dynamic and engaging approach. - Ability to deliver polished edits within a tentative duration of 5-10 minutes per video. - Proficiency in creativity and storytelling, even though I've not specified a particular style. - Willingness to work on a continual basis as the frequency of videos is high. Ideal Skills & Experience: - Prior experience in YouTube video editing. - Proven track record in creating engaging content. - Strong understanding of YouTube best practices. - Capability to work efficiently to meet deadlines. If you are passionate about YouTube content creation and excel in video editing, this could be ...

I am looking for a Dialux expert to design both indoor and outdoor lighting for a functional and task-oriented purpose. Key project requirements: - Design both indoor and outdoor lighting using Dialux - Prioritize functional and task-oriented lighting design aspects Ideal skills and experience: - Proven experience with Dialux software - Strong understanding of lighting design principles - Ability to balance functional and aesthetic aspects of lighting design Please note that while I do not have specific brands or models in mind, I am looking for a cost-effective solution. You should be comfortable exploring various options to find the most suitable and efficient lighting solutions. If you have a portfolio showcasing similar projects or relevant experience, I'd love to see it. Pl...

...meet project requirements - Convert AI/ML models into APIs that other developers can use - Perform statistical analysis on big data sets - Manage project infrastructure and the development of AI models and projects - Work with other machine learning engineers, data engineers, and AI engineers to develop machine learning models Below are the qualifications expected of an artificial intelligence engineer: Bachelor’s degree or several years of experience in computer science, data science, software development, or another related field; a master’s degree is recommended Solid understanding of common programming languages used in AI, such as Python, Java, C++, and R Advanced knowledge of statistical and algorithmic models as well as of fundamental mathematical concepts, s...