Last time only the tens changed. This time only the ones change.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Add to the cubes
23 + 4. The 2 tens stay. 3 ones and 4 ones make 7 ones. The answer is 27.
This works while the ones stay under ten. 3 and 4 is only 7.
When the ones still fit
23 + 4 is easy because 3 and 4 stay under ten. No bundle is needed, so the tens digit is left alone.
Check before you start
Add the ones in your head first. Under ten means the easy route. Ten or more means you will need a new bundle.
Step 2: Try It Yourself
Tap and try it out.
First number
and Add ones
Altogether
Tens
2
Ones
7
23 + 4 = 27
2 tens and 0 tens make 2 tens. Ones go with ones.
Step 3: Watch an Example
One step at a time.
Watch Leo Add Ones
Leo works out 23 + 4.
- Step 1
He looks at the rods. There are 2, and nothing joins them.
Step 4: Your Turn
Practice makes it stick.
More Shells
Problem 1 of 1
Ana has 21 shells. She finds 5 more. How many now?
shells
Add the Ones Only
1 of 3
32 + 5 = ?
2 of 3
14 + 3 = ?
3 of 3
25 + 4 = ?
Step 5: Quick Check
Show what you know.
Question 1 of 2
31 + 6 = ?
Question 2 of 2
Which part changes in 22 + 3?
What You Learned
- Ones join the ones. Tens stay as they are.
- 23 + 4 = 27.
- This works while the ones stay under ten.