Estimate and compare
Use easy numbers to find the closest answer.
Add percentages
Eight questions. No time limit.
- Questions answered
- 0 / 8
- Active time
- 0:00
Which answer is closest?
Use nearby easy numbers. Choose the option closest to the original calculation, not just to your estimate.
49 × 21 ≈ 50 × 20
One way to solve it
- Correct answers
- 0 / 8
This sends this round — score, settings, active time and task counts — to Studio AM with a random guest ID, and keeps sharing later rounds until you turn it off. No name, no individual answers, no drawings, and nothing from your earlier history.
How to play
Choose one of four answers. The answer locks when selected. Read the method, then choose Next question.
Round to numbers that make the operation easier. A benchmark helps locate the answer; it does not make an approximate value exact.
Only one option is closest to the original value. Review shows the rounded calculation and the exact value. A square root can stay in radical form so it is not rounded misleadingly.
Finish all eight questions to save a result in this browser. An unfinished round is not saved. Active time includes answers and review, but not background tabs. There is no time limit or speed bonus.
Use Tab and Enter or Space to choose an answer. Keys 1–4 also select answers, except when another control is focused.
History stays in this browser. Community sharing is off until you choose. Guest settings
Give feedback
Optional and off by default. Share starts, completions, replays and error categories with our team. No answers, drawings or names.
How this data is used