Skill: percent-of-a-number

Percent of a Number Practice

An endless supply of never-repeating percent problems with instant feedback. Benchmark percents, tricky percents, over-100% cases, discounts, and tips — one problem at a time.

1 Practice

Type your answer and press Check answer (or Enter). A wrong answer earns a hint first; a second miss walks you through the full solution.

Score 0 · Streak 0 · Problem 0

Score counts first-try correct answers. Streak counts consecutive correct answers.

Benchmark percents

How to enter answers

Plain numbers: type like 20 or 9.
Money: type a dollar amount like 9.90 or 32 — the $ is optional.

2 What you’ll practice

Every problem is generated fresh from 12 templates — a problem never repeats until its whole pool is used up.

Benchmark percents

50%, 10%, 25%, 75%, and 5% of friendly numbers — the 10% stepping stone does the heavy lifting.

25% of 80 → 20

Tricky & over-100%

15%, 35%, 45% via benchmark pieces, and percents over 100% (the answer beats the whole).

150% of 40 → 60

Discounts & tips

Real money: how much you save, the sale price, the tip, and the total with tip.

20% off $40 → save $8, pay $32

3 Watch out for these

The three mistakes students make most often with percents.

1. Decimal in the wrong place

Wrong: 25% of 80 = 2.5 × 80 = 200 Right: 25% → 0.25, so 0.25 × 80 = 20. Divide by 100, not by 10.

2. Answering the discount instead of the price

Wrong: “20% off $40” → $8 Right: $8 is the savings; the price is $40 − $8 = $32.

3. Capping percents at 100%

Wrong: “150% of 40 can’t top 40” Right: 150% = 1.5, and 1.5 × 40 = 60. Over 100% means more than the whole.

Review the lesson Open the percent tool Print a worksheet