2 + 7 and 7 + 2 both make 9. The order does not matter.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
This makes it easier
Counting on 2 is quicker than counting on 7. So start with the bigger part.
Test it rather than trust it
Build 3 + 5, count it, swap the groups, count again. The answer cannot move, because nothing was added or taken away.
It halves what you have to learn
Every fact you learn arrives with its swap for free. Knowing 2 + 7 means you already know 7 + 2.
Step 2: Try It Yourself
Swap the two parts and watch the total.
9
2
7
First tray
Second tray
2 and 7 make 9.
Step 3: Watch an Example
One step at a time.
Watch Ana Swap
Ana needs to work out 2 + 7.
- Step 1
Counting on 7 from 2 would take a long time.
Step 4: Your Turn
Practice makes it stick.
Sharing Grapes
Problem 1 of 1
Mia eats 3 grapes and Ben eats 6. How many grapes did they eat in all?
Same Total
Use the swap to make it easier.
1 of 2
1 + 8 = ?
2 of 2
2 + 6 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
3 + 5 = 8. So what is 5 + 3?
Question 2 of 2
Which is quicker to count on?
What You Learned
- Swapping the parts does not change the total.
- Start with the bigger number.
- Then you have fewer hops to count.