You now have four tools: doubles, near doubles, make ten, and take from ten.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Read the numbers first
Two numbers the same means a double. One apart means a near double. An 8 or 9 means make ten.
Step 2: Try It Yourself
Tap and try it out.
First ten
The rest
8 needs 2 more to make ten. Take 2 from the 7.
15 beads moved across in total.
15 beads moved across in total.
How many
That is 3 full fives, which is 15.
Step 3: In Real Life
Mental math at the store
5 + 6 is a near double. 9 + 4 is a make-ten. 8 + 2 is just counting on. A good shopper looks at the numbers before starting.
Step 4: Watch an Example
One step at a time.
Watch Ana Choose
Ana is given three facts: 6 + 6, 9 + 4, and 7 + 8.
- Step 1
For 6 + 6 she sees equal numbers and calls it a double.
Step 5: Your Turn
Practice makes it stick.
The Shop
Problem 1 of 2
A pen costs 9 pence and a rubber costs 7. What do they cost together?
pence
The Garden
Problem 2 of 2
Ana planted 6 seeds and Leo planted 7. How many seeds did they plant?
seeds
Which Strategy?
Name the strategy that fits the numbers best.
1 of 4
Which strategy fits 9 + 5 best?
2 of 4
Which strategy fits 7 + 7 best?
3 of 4
8 + 6 = ?
4 of 4
13 − 8 = ?
Slide the Beads
Build it, then check.
Slide 15 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 + 7 = ?
Question 2 of 2
Which strategy fits 6 + 7 best?
What You Learned
- Look at the numbers before you start working.
- Equal numbers mean a double. An 8 or 9 means make ten.
- More than one strategy can be right. Counting one by one is the slow one.
For the grown-up
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.
More than one road works — For 8 + 7 you could make ten or use the double 7 + 7. Both are good. Counting one by one is not.
Look before you calculate — By now you have several strategies: doubles, near doubles, making ten, taking from ten, and counting on. A skilled adder does not use the same one every time. They glance at the numbers first and choose. That glance takes a moment and saves far more.
What each pair of numbers is telling you — Same number twice? Use a double. One or two apart? Near double. One number is 8 or 9? Make ten. Adding 1, 2 or 3? Just count on — no strategy needed. Subtracting from a teen number with a big subtrahend? Take from ten. The numbers themselves signal which tool fits.
There is no single right method — Two children can solve 7 + 8 differently and both be correct — one through 7 + 7 = 14 then add one, the other through making ten. Math allows more than one good path. What matters is that your path is reliable and that you can explain it.
Let the numbers choose the tool — 6 + 7: near double. 6 + 6 = 12, one more, 13. 9 + 4: make ten. Move one across. 10 + 3 = 13. 13 − 9: count up from 9. Ten, eleven, twelve, thirteen. Four hops. Three problems, three tools. Look at the numbers before you start working.