Definition of Decomposing numbers.

• A. Break numbers into tens and ones.
• B. Break numbers into multiples of ten.
• C. Add numbers to get a larger number.
• D. Multiply digits of a number.

Answer: (A)

Decomposing numbers means breaking a number apart into parts that reflect its place value, such as tens and ones. For example, decomposing 47 into 40 and 7 shows what belongs to the tens place and what remains in the ones place. This helps with mental math and understanding how numbers are built from tens and ones, which makes addition and subtraction easier by working with those parts separately. The choice that aligns with this idea is breaking numbers into tens and ones. The other options describe different operations: breaking into multiples of ten ignores the ones part; adding numbers combines values to make a bigger number; multiplying digits is a separate operation on the digits themselves.