How do I explain "make a 10" to my 2nd grade son for his math homework?

2 answers

He could count his 10 fingers.

He could count out 10 Cheerios or M&Ms.

He could count his toes on one foot and add it to the number of toes on the other foot.

He could add:
5 + 5
6 + 4
7 + 3
8 + 2
9 + 1
i have no idea