Ten and something is the easiest kind of addition. 10 + 4 is 14, and you can hear it.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
So make a ten first
For 8 + 5, ask what 8 needs to reach ten. It needs 2. Take that 2 from the 5.
That leaves 3. Now the problem is 10 + 3, which is 13.
Complete the bigger one
Fill whichever number is closer to ten. It needs less taken from the other.
Step 2: Try It Yourself
Make the move yourself, then read the chain underneath.
First ten
The rest
8 needs 2 more to make ten. Take 2 from the 5.
13 beads moved across in total.
13 beads moved across in total.
How many
10 and 3 make 13.
Step 3: In Real Life
Rows on a tour bus
A tour bus has rows that seat 10. 8 people are in a row and 5 more get on. Two fill the row. Three go to the next. 13 people.
Step 4: Watch an Example
One step at a time.
Watch Ana Make Ten
Ana is asked for 9 + 6.
- Step 1
She sees the 9 is closest to ten, so she fills that one.
Step 5: Your Turn
Practice makes it stick.
Fruit Bowl
Problem 1 of 2
There are 9 apples and 7 oranges in a bowl. How many pieces of fruit are there?
pieces
Reading Time
Problem 2 of 2
Leo read 8 pages before lunch and 6 after. How many pages did he read?
pages
Make the Ten
Ask what the bigger number needs to reach ten.
1 of 4
9 + 4 = ?
2 of 4
8 + 7 = ?
3 of 4
7 + 6 = ?
4 of 4
5 + 9 = ?
Slide the Beads
Build it, then check.
Slide 13 beads across.
0 beads moved across in total.
0 beads moved across in total.
How many
Step 6: Quick Check
Show what you know.
Question 1 of 2
9 + 8 = ?
Question 2 of 2
In 7 + 8, which number is easier to fill to ten?
What You Learned
- Ten and some more is the easiest sum to say.
- Fill one number up to ten, then add what is left.
- Fill whichever number is closer to ten.
For the grown-up
This lesson is where the child adds within 20 by making ten, and chooses which addend to complete. Fluency within twenty is not speed for its own sake. Facts that come without thinking free up the working memory that the next four years of mathematics need, and a child recomputing 8 + 6 every time has nothing left over for the problem it sits inside.
Watch for finger counting that has gone underground — a pause, a glance away, lips moving. The strategy has not gone; it has just got quieter.
Short and often beats long and rare. Two minutes of the facts they nearly know is worth more than twenty minutes of the ones they already do.
Why we stop at ten on the way — Ten is the easiest number to add to. 10 + 4 is 14 and you can read the answer straight off the number. So instead of adding 8 + 5 in one go, we take a detour: build 8 up to 10 first, then add whatever is left over. The detour looks like extra work, but it swaps one hard step for two easy ones.
A worked case: 8 + 5 — Step 1: 8 needs 2 more to become 10. Step 2: split the 5 into 2 and 3. Step 3: give the 2 to the 8, making 10. Step 4: the 3 is left, so 10 + 3 = 13. Nothing was added or lost along the way — the 5 was only broken into pieces and moved.
You need the number partners for this — Making ten only works quickly if you know instantly what each number needs to reach ten: 9 needs 1, 8 needs 2, 7 needs 3, 6 needs 4, 5 needs 5. These are the number partners of ten. If you have to count them up each time, the strategy is slow. Learn the five pairs and the strategy becomes fast.
Fill the ten, then add the rest — 8 + 6. Eight needs two to make ten. Split the six into 2 and 4. 8 + 2 = 10 10 + 4 = 14 Always complete the ten from the bigger addend. It needs fewer moved across.