Math Facts come in families. Choose a number, i.e. '10'. When two numbers are added together to make 10. Those same two numbers, along with the number 10 can be used to create subtraction problems. When all these numbers are organized into sets using the same numbers, they are called "fact families." Can you find the patterns in the sets of make 10 and subtract from 10 seen below? Can you use this same concept using make 5? What about 20? Or even 100?
The fact families for 10 are:
0+10=10
10+0=10
10-0=10
(can discuss negative numbers 0-10= -10)
1+9=10
9+1=10
10-1=9
10-9=1
2+8=10
8+2=10
10-2=8
10-8=2
3+7=10
7+3=10
10-3=7
10-7=3
4+6=10
6+4=10
10-4=6
10-6=4
5+5= 10 (double)
10-5=5
Here is another way to show fact families: