Purpose

A simple single-page web app for children aged five to eight. It teaches number recognition while children practise addition, subtraction, multiplication, and division. The experience should be playful, clear, and usable without adult help. Interface The page contains one centred calculator with a large display, number buttons from 0–9, four operation buttons, equals, clear, an optional audio button, and a friendly illustrated guide. Buttons must be large, well spaced, clearly labelled, and suitable for touch. There are no menus, accounts, advertisements, pop-ups, or external links. Behaviour Children select a number, an operation, another number, and equals. The app displays the complete equation, such as “4 + 3 = 7.” Inputs are limited to two-digit whole numbers. Subtraction cannot produce negative answers, and division must produce whole-number results. Clear resets the equation. Invalid input triggers a gentle instruction such as “Choose one more number.” Learning Features Selecting a number displays its written name, such as “7 — seven.” The audio button can read numbers and equations aloud. Each result includes a simple visual explanation. Addition and subtraction show objects being added or removed. Multiplication shows equal groups, while division shows objects shared between groups. The guide responds with encouraging messages. After three calculations, it may offer an optional challenge. Incorrect answers invite another attempt and display a helpful hint without negative language. Design and Technical Scope Use calm, bright colours, rounded shapes, strong contrast, and minimal animation. Do not rely on colour alone to identify operations. Support touch, mouse, and keyboard input. Audio is muted by default. Build the responsive app with HTML, CSS, and JavaScript for modern phones, tablets, and desktops. All calculations run locally. No login, personal-data collection, or server is required. Progress resets on refresh.