Estimate and compare
Use easy numbers to find the closest answer.
Continue your unfinished round
Your answers are saved in this tab. Continue from where you left off.
Continuing uses no additional practice start.
Discard the unfinished round?
Your answers from this round will be discarded. You can choose your settings before starting a new round.
Starting the new round uses one practice start.
Example
Example
49 × 21 ≈ 50 × 20
Choose the closest estimate.
Add percentages
Your last settings are ready. Change them whenever you like.
8 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.
One way to solve it
Explore the method
Use easy nearby numbers, then check which option is closest to the original value.
On by default unless you turn it off. Saved choices are kept. Shares starts, completions, replays and error categories. For ChatGPT visits, starts and completions may include the first QuickenBrain page and country. No answers, drawings or names.
How this data is usedHelp
Choose one answer. 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. The number keys also select answers, except when another control is focused.
About this practice
Learn a method
Estimate with useful benchmarksUse easy numbers to find the closest answer.
Report a problem
On by default unless you turn it off. Saved choices are kept. Shares starts, completions, replays and error categories. For ChatGPT visits, starts and completions may include the first QuickenBrain page and country. No answers, drawings or names.
How this data is used