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Specific Tricks

Level 17 / build-up

Add via sub (3d + near-round)

3 visual steps / add near round

1. Use round

234 + 9981. Use roundAdd the nearby round number.1234 + 1000 = 12342remove 23answer 1232
Add the nearby round number.

Add the nearby round number.

2. Remove extra

234 + 9982. Remove extraSubtract the extra amount.1234 + 1000 = 12342remove 23answer 1232
Subtract the extra amount.

Subtract the extra amount.

3. Final answer

234 + 9983. Final answerKeep the adjusted total. Read answer answer 1232Keep the adjusted total.
Keep the adjusted total.

Keep the adjusted total.

Practice Level 17

Name the shape first; the shortcut stays small.

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