The big ideaPartners are two numbers that make ten, and tens partners make a hundred.
How it works
Partners are two numbers that make ten, like 2 and 8.
Every number up to ten has exactly one partner. Five is its own partner.
On the frame, a pair of partners fills the ones row, and then it trades for one ten.
Tens partners make a hundred: ninety and ten, or twenty and eighty.
Pairs that make ten.
Example 1: Find the partner of 2
A tray has ten spots and 2 are filled. Count the empty spots: there are 8.
2 + 8 = 10
Two and eight are partners.
2 across a row of ten: 8 more fill it.
Example 2: Five and five
A tray has 5 cubes in it and 5 spots left.
5 + 5 = 10
Five is its own partner.
5 across a row of ten: 5 more fill it.
Example 3: A partner trade
Put 7 on the ones row and add 3, its partner.
7 + 3 = 10. The ones row is full.
Ten ones trade for one ten, so partners make a quick trade.
After the trade: one ten and no ones.
Example 4: Tens partners
Four tens and six tens: 40 + 60.
The tens row is full, and ten tens trade for one hundred.
40 + 60 = 100
One hundred is one bead on the top row.
Example 5: Use partners to add
In 4 + 8 + 6, spot the partners first.
4 + 6 = 10
10 + 8 = 18
4 + 8 + 6 = 18
Words to know
partners
Two numbers that make ten.
tens partners
Two tens numbers that make a hundred, like 20 and 80.
full row
A row with ten beads slid across.
trade
Ten beads on one row become one bead on the next row up.
Watch out
The partner of a number is what makes ten, not what makes nine.
Tens partners make a hundred: 30 and 70, not 30 and 60.
Look for partners first when you add three numbers.
Try it
What is the partner of 6, the number that makes ten with it?
70 + ? = 100
What is 4 + 8 + 6?
Do 6 and 5 make ten?
Answers: 1. 4 · 2. 30 · 3. 18 · 4. no
Try at homeAsk a grown-up to say a number from one to nine. You say what to add to make ten. Take turns. Then try with tens, like thirty, and make a hundred.
For grown-upsPlay Partners: you say a number from one to nine, your child says what to add to make ten. Then try tens, like thirty, to make a hundred.
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