Number bonds

Walt: We are learning number bonds to 10,20,50 and 100

Number Bonds 

1. To 10
    3+7=10
    4+6=10

2. To 20
    5+15=20
    8+12=20

3. To 50
    9+41=50
    1+49=50

4. To 100
    0+100=100
    3+97=100

5. What is a Number bond?
    A Number bond is two numbers that make a tidy number.

I liked doing number bonds because I got to add numbers together to make a tidy number.

What do you think a number bond is??