Fact Families

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:

Kinder_Craze

  

The First Grade Parade: Adding and subtracting in fact families.

Make 10

Source

Addition:

0+10 = 10

1+9= 10

2+8=10

3+7=10

4+6=10

5+5= 10 (double)

6+4=10

7+3=10

8+2=10

9+1=10

10+0=10

Subtraction:

10-0=10

10-1=9

10-2=8

10-3=7

10-4=6

10-5=5

10-6=4

10-7=3

10-8=2

10-9=1

Games to Play:

Make 10

Lay out 25 cards face up in rows of 5 using number cards 0-10. Each partner takes a turn choosing 2 cards that will equal 10 when added together. The equation created is written in the students' math games notebook.

Fish for 10

Play like Go Fish, except that the students are trying to get a card from their partner so that they can make 10. (i.e., The student has the number 2 and asks for the number 8. If the partner doesn't have the number 8, then the first student takes a card from the pile.)