Week 11 · Add and subtract tens
Tuesday
Add tens to a number
// Bigger numbers, tens and ones
⏱ about 15 min
Tuesday: Add tens to a number
Hazel has 34 leaves for her art.
Bennie brings her 20 more leaves.
"I can add the tens," says Hazel.
"The ones stay the same."
Learn it: add the tens
34 is 3 tens and 4 ones.
20 is 2 tens and 0 ones.
3 tens and 2 tens make 5 tens.
The 4 ones stay the same.
So 34 plus 20 is 54.
Hazel counts on by tens: 34, 44, 54.
ADD THE TENS
- Read the question.
- Tap your answer.
34 + 20 = ?
25 + 30 = ?61 + 10 = ?
47 + 40 = ?
HAZEL'S LEAVES
- Read the question.
- Tap your answer.
Hazel has 16 leaves. She finds 30 more. How many now?Bennie has 52 stones. He finds 20 more. How many?
There are 38 ducks. Then 50 more come. How many?
ADD 10 EACH TIME
- Start with 13.
- Add 10 each time.
11st
22nd
33rd
44th
55th
Adding tens changes only the tens digit.
| Number sentence | True or false? |
|---|---|
| 34 + 20 = 54 | ? |
| 45 + 10 = 46 | ? |
| 72 + 20 = 92 | ? |
| 18 + 40 = 58 | ? |
WHY THIS EXERCISE45 plus 10 is 55, not 46.
Try it
Make 2 piles of 10 and 6 ones.
That is 26.
Add 1 more pile of 10.
Count again. Is it 36?
That is 26.
Add 1 more pile of 10.
Count again. Is it 36?
Draw 26 with tens and ones. Then add a ten.
Word Spot: then, think
Here are new sight words.
Look at each word. Say it. Spell it.
Then: T-H-E-N.
Think: T-H-I-N-K.
FIND THE WORD
- Listen to the word.
- Tap it.
Find the word you hear.
Find the word you hear.
Find the word you hear.
Find the word you hear.
FILL THE GAP
- Listen to the sentence.
- Tap the missing word.
First we plant, ___ we water.
What do you ___?
You added tens! Tomorrow we add ones.