A group can be split into two parts. The group is called the whole.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
A picture of the parts
A number bond shows the whole on top and the two parts below.
The same 5 apples can be split a different way. Both are correct.
Step 2: Try It Yourself
Move the apples and watch the bond change.
5
3
2
First tray
Second tray
3 and 2 make 5.
How many
5 and 5 make 10. There are 5 empty spaces.
3 and 2 make 5.
Step 3: In Real Life
Sharing crayons
You have 6 crayons. You give some to a friend. 4 for you and 2 for them. Or 3 and 3. The whole is still 6. That is a number bond.
Step 4: Watch an Example
Watch one set become a bond.
Reading a Bond
Ben has 6 apples. He puts some in each tray.
- Step 1
He counts the whole group first. That is 6.
Watch Leo Make a Bond
Leo has 7 stars. He puts 5 in one tray. Leo starts. You finish.
- Step 1
Leo counts all his stars first. The whole is 7.
Stars
Step 5: Your Turn
Practice makes it stick.
Snack Time
Problem 1 of 13
Mia has 7 grapes. She eats 3. How many are left?
The Pencil Box
Problem 2 of 13
Ben has 8 pencils. 2 are in his box. The rest are on his desk. How many are on his desk?
Split It Your Way
Make 6 stars. Then find two different ways to split them.
Problem 3 of 13
6
1
5
First tray
Second tray
1 and 5 make 6.
Parts and Wholes
Find the missing part, or the whole.
Problem 4 of 13
The whole is 5. One part is 1. What is the other part?
Problem 5 of 13
Count both trays. What is the whole?
Problem 6 of 13
The whole is 7. One part is 5. What is the other part?
Find the Mistake
A friend split some things. Can you spot the slip?
Problem 7 of 13
Sam looks at his trays. He says the whole is 5. What went wrong?
Problem 8 of 13
What is the whole?
Problem 9 of 13
Ana splits 7 into 3 and 5. What went wrong?
Problem 10 of 13
7 is 3 and how many?
Same Whole?
Split it any way. Is the whole the same?
Problem 11 of 13
Mia splits 6 into 4 and 2. Leo splits 6 into 3 and 3. Who is right?
Problem 12 of 13
Ben moves one apple to the other tray. What happens to the whole?
Show the Missing Part
Build it, then check.
Problem 13 of 13
5 is 3 and how many? Show that part.
How many
Step 6: Quick Check
Show what you know.
Question 1 of 2
The whole is 6. One part is 2. What is the other part?
Question 2 of 2
Look at the trays. What is the whole?
Ready for more?Optional. Past the lesson, for anyone who wants it.
Stretch 1 of 1
The whole is 8. The two parts are the same. What is each part?
What You Learned
- A whole can be split into two parts.
- A number bond shows the whole and both parts.
- One group can be split in more than one way.
For the grown-up
Counting and knowing how many are different skills. A child can recite to twenty and still recount a row of six every time they are asked, because the last number said has not yet become the answer to "how many".
Watch for recounting. If they count a group, are asked how many, and start again from one, the link has not formed yet. It is extremely common at this age and is not a memory problem.
When it happens, count together slowly and then close your hand over the group and ask again. Hiding the objects is what forces the number to stand in for them.
A bond reads both ways — Top to bottom it says the whole splits into two parts. Bottom to top it says the parts join into the whole. One picture, two ideas.
One bond, four sentences — A bond of 5 with 3 and 2 gives 3 + 2 = 5, 2 + 3 = 5, 5 − 3 = 2 and 5 − 2 = 3. Learning the bond is worth four times learning a fact.
Read the bond both ways — The whole is 5. The parts are 3 and 2. Read it downwards: 5 splits into 3 and 2. Read it upwards: 3 and 2 join to make 5. Same picture. Both are true. 3 + 2 = 5 and 5 − 3 = 2