Sometimes the ones add up to ten or more. Then you make a new ten.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Watch what happens
38 + 25. Tens: 5 tens. Ones: 8 and 5 makes 13. That is too many loose ones.
Bundle them
Bundle ten of the 13 into a rod. Now 6 tens and 3 ones.
It is a ten, not a one
People sometimes say "carry the one". It is not a one. It is one ten.
When a new ten appears
Add 47 + 26. The ones give 7 + 6 = 13, which is more than nine ones can hold. Ten of those ones bundle into a single ten, leaving 3 in the ones place and sending one ten across. This is what carrying is: a bundle moving to the column where it belongs.
Finishing the sum
After the bundle moves, the tens column holds 40 + 20 plus the carried 10, which is 70. With the 3 ones left over the answer is 73. Nothing was invented and nothing was lost — thirteen ones were simply rewritten as one ten and three ones.
The classic mistake
The usual error is writing 13 in the ones place, or writing the 3 and forgetting the carried ten. Guard against it by estimating first: 47 + 26 is roughly 50 + 25, so about 75. An answer of 613 or 63 fails that check immediately.
Step 2: Try It Yourself
Count the loose ones before you bundle.
First number
and Second number
Altogether
Tens
5
Ones
13
38 + 25 = 63
There are 13 loose ones. Ten of them can become one more ten.
Step 3: Watch an Example
One step at a time.
Watch Leo Make a New Ten
Leo adds 38 and 25.
- Step 1
He counts the rods: 3 and 2 makes 5 rods.
Step 4: Your Turn
Practice makes it stick.
Two Shelves
Problem 1 of 2
One shelf holds 27 books and another holds 46. How many books in all?
books
Collecting
Problem 2 of 2
Ana has 55 shells and finds 29 more. How many does she have now?
shells
Bundle When You Need To
Check the ones first. They tell you whether a bundle is coming.
1 of 4
46 + 27 = ?
2 of 4
35 + 28 = ?
3 of 4
42 + 31 = ?
4 of 4
59 + 26 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
29 + 34 = ?
Question 2 of 2
When you bundle ten ones, what do you get?
What You Learned
- When the ones reach ten, bundle them into a ten.
- The new ten joins the other tens.
- It is one ten, not one one.