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Specific Tricks

Level 26 / mastery

Sub via add (3d near-round)

3 visual steps / subtract near round

1. Use round

1234 - 9991. Use roundSubtract the nearby round number.11234 - 1000 = 2342add back 13answer 235
Subtract the nearby round number.

Subtract the nearby round number.

2. Add back

1234 - 9992. Add backAdd back the extra amount.11234 - 1000 = 2342add back 13answer 235
Add back the extra amount.

Add back the extra amount.

3. Final answer

1234 - 9993. Final answerKeep the adjusted total. Read answer answer 235Keep the adjusted total.
Keep the adjusted total.

Keep the adjusted total.

Practice Level 26

Name the shape first; the shortcut stays small.

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