Rounding, random numbers and maths functions.
✍️ 3 exercises + code challenge in this lessonThe Math object provides mathematical constants and functions:
Math.round(), Math.ceil(), Math.floor(), Math.trunc()Math.max(), Math.min(), Math.abs()Math.pow(), Math.sqrt()Math.PIMath.random(): a random number from 0 (inclusive) to 1 (exclusive).A random integer between min and max: Math.floor(Math.random() * (max - min + 1)) + min
Mastering JavaScript Math helps you write clean and reliable JavaScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
<pre id="out"></pre>
<script>
const log = (...a) => document.getElementById("out").textContent += a.join(" ") + "\n";
log(Math.round(4.6), Math.ceil(4.1), Math.floor(4.9));
log("max:", Math.max(3, 9, 1), "min:", Math.min(3, 9, 1));
log("sqrt(64):", Math.sqrt(64), "PI:", Math.PI.toFixed(4));
const dice = () => Math.floor(Math.random() * 6) + 1;
log("Dice rolls:", dice(), dice(), dice());
</script>
<button onclick="location.reload()">Roll again</button>Check what you learned in “JavaScript Math”.
Round the number down.
Math.(4.9) // 4
What range does Math.random() return?
Log the largest of 7, 42 and 13 using Math.max().
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