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To solve the expression by breaking down , follow these steps:
Thus, the detailed decomposition to match the answer format is: .
If we have 67 blocks in total, how many blocks will remain if we remove 5 tens and 4 ones?
Breaking 9 into 7 + 2 is strategic! When you add 33 + 7, you get the round number 40, which makes the final step (40 + 2 = 42) much easier to calculate mentally.
Direct addition works too! But decomposition helps you understand place value better and makes mental math faster, especially with larger numbers.
Look for combinations that create round tens! Since 33 needs 7 more to reach 40, break 9 into 7 + 2. This strategy works for any addition problem.
Yes! You could write it as 30 + 3 + 9, then add 30 + 9 = 39, then 39 + 3 = 42. Both methods work, so choose what feels easier!
Because 3 + 5 = 8, not 9! The decomposition must add up to the original number. Always double-check that your broken parts equal the whole number.
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