Home / Hands-on activities / Number Bond Builders

Math activity

Number Bond Builders

Grab 5 buttons or coins in two colors! Split them into two groups and find every way to make 5: 1 and 4, 2 and 3, and more.

Hands OnAbout 30 minutesScreen-freeParent help expected

Materials and setup

How this changes by age

Pre-K (ages 3–4)

Grab 5 buttons or coins in two colors! Split them into two groups and find every way to make 5: 1 and 4, 2 and 3, and more.

Difficulty 1 of 3

Steps

  1. Get 5 counters (buttons, coins, or candies) in two colors — 3 red and 2 blue, for example.
  2. Place all 5 in a line. Separate them into two groups. How many in each group?
  3. Find all the ways to split 5: (0,5), (1,4), (2,3), (3,2), (4,1), (5,0).
  4. Draw circles connected by lines to show each number bond (a big circle with 5, two small circles with the parts).
  5. Sing or chant the pairs: 'One and four make five! Two and three make five!'
  6. Tell a grown-up one thing that surprised you.

Learning objectives

  • Find all pairs of numbers that add to 5
  • Represent number bonds visually with part-part-whole diagrams
  • Understand that a number can be decomposed in multiple ways

Kindergarten (ages 5–6)

Build number bonds for 10 using counters, ten-frames, and drawings. Master all the ways to make 10, which is the foundation for mental math.

Difficulty 2 of 3

Steps

  1. Use 10 counters in two colors. Place them on a ten-frame.
  2. Flip some counters to the other color. How many of each color? That is a number bond for 10!
  3. Find ALL the ways to make 10: 0+10, 1+9, 2+8, 3+7, 4+6, 5+5, and the reverse of each.
  4. Draw a number bond diagram for each pair. The whole is 10, the parts are the two numbers.
  5. Quiz game: parent says a number (e.g., 7), child says the partner that makes 10 (3). Go faster and faster!
  6. Tell a grown-up one thing that surprised you.

Learning objectives

  • Find all pairs of numbers that sum to 10
  • Use ten-frames to visualize number bonds for 10
  • Recall number bonds for 10 with increasing fluency

Early elementary (ages 6–8)

Extend number bonds to 20 and beyond. Use number bonds to develop mental addition and subtraction strategies, and connect to fact families.

Difficulty 2 of 3

Steps

  1. Review number bonds for 10. Then extend: what pairs make 20? (11+9, 12+8, 13+7, etc.)
  2. Use number bonds to solve addition: 8 + 7 = 8 + 2 + 5 = 10 + 5 = 15 (bond 7 into 2 and 5).
  3. Use number bonds for subtraction: 15 - 8 = ? Think: 8 + ? = 15. The missing bond is 7.
  4. Write fact families for 5 number bonds: if 7 + 3 = 10, then 3 + 7 = 10, 10 - 7 = 3, 10 - 3 = 7.
  5. Play 'Make 100': draw two cards, make a 2-digit number, and find what number you need to add to make 100.
  6. Solve 8 word problems using number bond thinking.
  7. In one sentence, tell a parent or sibling what surprised you today.

Learning objectives

  • Extend number bond knowledge to 20 and 100
  • Use number bonds as a mental math strategy for addition and subtraction
  • Write complete fact families from number bonds

Upper elementary (ages 8–10)

Apply number bond thinking to fractions, decimals, and algebra. Find pairs that sum to 1, pairs that sum to 100, and use part-whole reasoning to solve equations.

Difficulty 3 of 3

Steps

  1. Fraction bonds to 1: find pairs like 1/4 + 3/4 = 1, 2/5 + 3/5 = 1. List 10 pairs that make 1 whole.
  2. Decimal bonds to 1: 0.3 + 0.7 = 1, 0.25 + 0.75 = 1. List 8 decimal pairs that make 1.
  3. Percentage bonds to 100%: 35% + 65% = 100%. Use these for quick mental percentage calculations.
  4. Algebraic bonds: if a + b = 20, and a = 13, what is b? Solve 8 equations using number bond thinking.
  5. Apply to real world: if you have spent 3/8 of your allowance, what fraction remains? If a store has a 40% off sale, what percentage do you pay?
  6. Create a 'Bonds Reference Sheet' showing key bonds for 10, 100, 1, and common fractions.
  7. In one sentence, tell a parent or sibling what surprised you today.

Learning objectives

  • Find fraction and decimal pairs that sum to 1
  • Apply number bond reasoning to solve algebraic equations
  • Connect number bonds to real-world percentage and fraction problems

Safety and evidence note

Read the full activity before beginning. An adult should supervise tools, heat, food, outdoor work, movement, and experiments as appropriate. Completion records that the activity was done; the child’s explanation, work sample, photo, or demonstration is stronger evidence of learning than a completion check alone.

Related math activities

Addition and Subtraction Stories

Use toy animals to tell math stories. '3 ducks are swimming. 2 more come. How many now?' Act it out and count together.

Algebra Adventures: Patterns and Variables

Build a pattern with red and blue blocks — red, blue, red, blue! What comes next? Find patterns on shirts, tiles, and bricks too.

Angle Explorers

Explore turns and corners! Open a book wide or just a little bit. Discover that doors, scissors, and your arms all make angles when they open and close.

Animal Counting Corral

Round up toy animals into corrals (bowls or boxes) and count how many are in each group. Practice counting up to 10 with one-to-one correspondence.

Browse all 575 activities · Explore course syllabi