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A written description of decomposition

Example 1: 74 - 38

tens ones

Try to subtract the ones first. There are four ones and eight ones have to be taken away. Rename one of the 7 tens as 10 ones, leaving 6 tens.

tens ones

Add the 10 ones to the 4 ones giving 14 ones. 74 is now 6 tens 14 ones i.e. "sixty fourteen".

tens ones

Now it is easy to subtract ones: 14 ones take away 8 ones is 6 ones.

Now subtract the tens. 6 tens take away 3 tens is 3 tens.

Tens ones

74 take away 38 is 36.