Addition of Tens and Ones: Make a Ten to Add

Introduction:

In this session, you will learn how to make a ten and add. In the previous session learned about add tens and ones using models.

1. Find 21 + 7, use blocks to add the numbers. Then draw what you did.

2tens 1 one + 7 ones

21 + 7 = 28.

Draw the model and show the answer for 21 + 7 =?

Add ones first. 1one + 7 ones = 8 ones.

Then add with tens.

2tens + 8 ones= 28.

Solve the word problems below.

2. John ate 20 muffins. His friend gave him 3 more muffins. How many muffins he ate in all?  Use the pictures and find the answer.

20 + 3 =___

20 muffins + 3 muffins = 23 muffins.

John ate 23 muffins in all.

Draw blocks to add.

3.Find 57 + 12.

7 + 2 =____

50 + 10 =____

57 + 12 =____

Introduction:

1. What strategy we can use to find 7 + 6? How can we use the sum for 7 + 6 to find 27 + 6?

We can use blocks or open number line to find the answer.

Answer:

We can make ones to ones to make a ten.

27 + 6 =?

27 + 3 + 3 =

7 ones + 3 ones = 10 ones

10 ones = 1ten.

2tens + 1 ten + 3 ones=

3tens and 3 ones

Now we have 3tens and 3 ones

30 + 3 = 33

So, 27 + 6 = 33

Sometimes we can’t make a ten when we add. Here given example:

Add 32 + 7  

Answer:

32 + 7 =?

Add ones first.

2ones + 7 ones = 9 ones.

Then 3tens + 9 ones = 39.

2.Draw blocks and make a ten to add.

Think: 47 + ___ =50

So, break apart 7 into___ + ____.

50 + ___ =____

So, 47 + 7 = ____.

We can break 7 into 3 and 4. still we have 4 to add with 50

Think: 47 + 3 = 50

So, break apart 7 into 3 + 4.

50 + 4 = 54

So, 47 + 7 = 54.

3. Jamal has 56 mangoes. His sister gives him 8 more mangoes, How many mangoes does Jamal have now? Draw blocks to show your work.

Number of mangoes Jamal has = 56

His sister gave him some mangoes = 8

Total mangoes he has now. = 56 + 8

Use blocks and add.

Make a ten and add.

Break 8 ones = 4 + 4

56 + 4 = 60, still need to add 4 more.

So, 60 + 4 = 64

4. Team A scored 25 points in first round of Quiz competition, then they scored 9 more Points extra. How many points did they score in all? Draw blocks and give the answer.

25 + 9 = ___

Team A scored points in 1^st round = 25

Scored extra points. =    9

Total score = 25 + 9

Draw model and add.

Make a ten and add

Break 9 into 5 + 4

So, 25 + 5 = 30

Still need to add 4

30 + 4 = 34

They scored 34 points in the quiz competition.

Exercise

1. Draw blocks and make a 10 to add 18 + 6 =
2. Add. Use or draw blocks to help. 36 + 9 =
3. Explain how to find 14 + 8 =.
4. Explain how to use the make 10 strategies to find 38 + 5=
5. Lisa knits 13 sweaters. then she knits 9 sweaters. How many sweaters does Lisa knit in all? Use blocks to find the answer.
6. Sam has 25 apples. Then she bought 7 more apples. How many apples does she have now.?
7. Write the missing numbers. Use place-value blocks if you need to.

 What We Have Learned:

• Use our knowledge of ten to help make addition problems easier to solve.