Skip to content

Learn

Specific Tricks

Level 27 / mastery

Sub via add (4d near-round)

3 visual steps / subtract near round

1. Use round

56780 - 99981. Use roundSubtract the nearby round number.156780 - 100002add back 23answer 46782
Subtract the nearby round number.

Subtract the nearby round number.

2. Add back

56780 - 99982. Add backAdd back the extra amount.156780 - 100002add back 23answer 46782
Add back the extra amount.

Add back the extra amount.

3. Final answer

56780 - 99983. Final answerKeep the adjusted total. Read answer answer 46782Keep the adjusted total.
Keep the adjusted total.

Keep the adjusted total.

Practice Level 27

Name the shape first; the shortcut stays small.

Start Level