Adding Within 20: Number Bonds Adventure

Words to Know

Number bond

Two numbers that join to make a bigger number

9 and 1 are a number bond for 10!

Make 10

A trick where you build a 10 first, then add what's left

To add 8 + 7, make 10 (8+2), then add 5!

Doubles

Two of the SAME number added together

5 + 5 = 10 is a doubles fact!

Ten frame

A box with 10 spots to help you see numbers

Fill 9 spots and 1 more makes 10!

Join

To bring two things together

8 and 2 join to make 10!

Check What You Learned

Fun Facts

• Number bonds are pairs of numbers that combine to make a given total

  Source: Singapore Math methodology, adopted in CCSS.MATH.CONTENT.1.OA.C.6

• The "make 10" strategy: to add 8 + 7, decompose 7 into 2 + 5, then (8 + 2) + 5 = 10 + 5 = 15

  Source: CCSS.MATH.CONTENT.1.OA.C.6

• Number bonds of 10: 1+9, 2+8, 3+7, 4+6, 5+5, 6+4, 7+3, 8+2, 9+1

  Source: standard arithmetic

• Number bonds of 20: 10+10, 11+9, 12+8, 13+7, 14+6, 15+5

  Source: standard arithmetic

• "Doubles" are pairs of the same number: 5+5=10, 10+10=20

  Source: CCSS.MATH.CONTENT.1.OA.C.6

• The make-10 strategy reduces cognitive load by leveraging memorized bonds of 10

  Source: Boaler, J., 2016, "Mathematical Mindsets"