Taking tens away works like taking ones away. Count what is left.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Count the rods left
4 tens take away 1 ten leaves 3 tens. That is 40 − 10 = 30.
Taking them all
If you take away every rod, nothing is left. 30 − 30 = 0.
Subtraction works the same way
5 tens take 2 tens is 3 tens, because 5 − 2 = 3. Once the unit is fixed, the old facts do the work.
Check by adding back
30 + 20 should return 50. Undoing your subtraction is the fastest check there is.
Step 2: Try It Yourself
Tap and try it out.
Start with
Taken away
What is left
Tens
3
Ones
0
40 − 10 = 30
Take 10 away from 40. The faded blocks are the ones that left.
Step 3: Watch an Example
One step at a time.
Watch Leo Take Tens
Leo works out 40 − 20.
- Step 1
He starts with 4 rods.
Step 4: Your Turn
Practice makes it stick.
Sharing Stickers
Problem 1 of 1
Ana has 30 stickers. She gives away 10. How many are left?
stickers
Take the Tens Away
1 of 3
20 − 10 = ?
2 of 3
40 − 30 = ?
3 of 3
20 − 20 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
30 − 20 = ?
Question 2 of 2
40 − 40 = ?
What You Learned
- Taking away tens leaves whole tens.
- 40 − 10 = 30.
- Taking away all of them leaves 0.