## Using friends of ten with subtraction within 20.

An alternate way of considering subtraction within 20 is to use the ten in the teens. That is, 14 – 6 can be determined by subtracting the 6 from 10 before adding the remaining 4, (10 – 6 + 4). This makes use of the standard partition of 14 (= 10 + 4), and draws on friends of ten rather than decomposing the 6 into 4 and 2. This method of subtraction is more popular when using Chinese numbers compared to English numbers.