Code Studio0 / 332 tasksLeave studioHome

Beginner

Intermediate

Advanced

Expert

Free practice

Auto-run

<main class="card">
  <h1>My calculator</h1>
  <!-- Your inputs, button and result go here -->
</main>

Projects · Beginner

Your own calculator

Now build a calculator of your own. Pick one: a BMI calculator, a unit converter, a discount calculator, an age-in-days calculator, a grade-average calculator, or invent your own. There is no single right answer: the tasks say what yours must do, and you decide how.

Exam conditions

No hints and no answers, and nothing ticks while you work. Run and test your code as often as you like. When you are ready, submit it: you get your mark, then the feedback and the model answers.

Your calculator needs at least one input box and a button. Give every input a label.
Pressing the button must change what is on the page (show an answer).
Different inputs must give different answers, so it really calculates.
Empty boxes must not break it: no NaN, undefined or Infinity on the page.
Put the calculation in a function of your own.
Make it look good: at least eight CSS declarations of your own, including a colour.

Exams are marked when you submit. Your work and your best mark are saved in this browser only.