Estimate It
No calculator this time. Round the numbers, work it out in your head, and see how close you get.
Daily round
Today's 10 estimates
A medium round, the same for everyone today.
Free play
No rounds played at this level yet.
How to play
- Each round has ten calculations. Type your estimate and lock it in.
- Within 5% of the exact answer scores 100 points, within 10% scores 75, within 25% scores 50 and within 50% scores 25.
- After each one you see the exact answer and the rounding shortcut that gets you close.
The shortcuts
- Round to the first digit: 48 × 21 is about 50 × 20 = 1,000. The exact answer is 1,008.
- Compatible numbers for division: 467 ÷ 8 is about 480 ÷ 8 = 60, because 8 goes into 48 evenly.
- Friendly percents: 24% is about a quarter, 49% is about a half, and 10% just moves the decimal point.
- Tips: find 10% of the rounded bill, then double it for 20%, or add half again for 15%.
Why estimate?
A quick estimate tells you whether a calculator answer makes sense. If you meant to type 48 × 21 and the screen says 10,080, the estimate of 1,000 shows a slip straight away.
Your scores
Your best round per level is saved in this browser only. No account, and nothing is sent anywhere.