All the solutions provided inÂ **McGraw Hill My Math Grade 5 Answer Key PDF Chapter 5 Lesson 10 Subtract Decimals **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 5 Answer Key Chapter 5 Lesson 10 Subtract Decimals

To subtract decimals, line up the decimal points. Then subtract digits in the same place-value position.

**Math in My World**

**Example 1**

The table shows the average lengths of the three longest bones in the human body. How much longer is the average femur than the average tibia?

Find 19.8 – 16.9.

Estimate 20 – 17 = _____________

So, the average femur is ____________ inches longer than the average tibia.

Subtraction and addition are inverse operations. Inverse operations are operations that undo each other.

Check: Use addition to check your answer.

____________ + 16.9 = 19.8.

Answer:

The addition is 2.9 + 16.9 = 19.8

The average femur is 2.9 inches longer than the average tibia.

Explanation:

**Example 2**

Find 6.3 – 4.78.

Estimate 6 – 5 = ____________

So, 6.3 – 4.78 = ____________

Check: Use addition to check your answer.

____________ + 4.78 = 6.3

Answer:

1.52

1.52 + 4.78 = 6.3

Explanation:

**Talk Math**

Explain the strategy used in Exercise 1 to subtract the decimals.

Answer:

1. At first, to subtract the decimals we need to line up the decimal points and add extra zeros to assist in mental calculations so that both numbers end in the same place value.

2. Subtract the digits in the same place value positions. Rename if necessary.

3. Bring down the decimal point straight down in the difference. Write the answer.

Hence this is the strategy we used in Exercise 1 to subtract the decimals.

**Guided Practice**

**Subtract. Use addition to check your answer.**

Question 1.

Estimate: 6 – 3 = _____________

So, 5.5 – 3.2 = ______________

Check

___________ + 3.2 = 5.5

Answer:

3, 2.3 and 2.3.

Explanation:

Estimate: 6 – 3 = 3

So, 5.5 – 3.2 = 2.3

Check

2.3 + 3.2 = 5.5

Question 2.

Estimate: 70 – 10 = _____________

So, 72.4 – 12.5 = ______________

Check

___________ + 12.5 = 72.4

Answer:

60, 59.9, 59.9

Explanation:

Estimate: 70 – 10 = 60

So, 72.4 – 12.5 = 59.9

Check

59.9+ 12.5 = 72.4

**Independent Practice**

**Subtract. Use addition to check your answer.**

Question 3.

Answer:

20.34

Explanation:

Given,

29.34 and 9

The subtraction of the given numbers is 20.34.

Now let us check the answer by doing an addition

9 + 20.34 = 29.34

Hence the answer is correct.

Question 4.

Answer:

0.2

Explanation:

Given,

0.4 and 0.2.

The subtraction of the given numbers is 0.2

Now let us check the answer by doing an addition

0.2 + 0.2 = 0.4

Hence the answer is correct.

Question 5.

Answer:

$7.32

Explanation:

Given,

$9.67 and $2.35

The subtraction of the given numbers is $7.32

Now let us check the answer by doing an addition

$7.32 + $2.35 = $9.67

Hence the answer is correct.

Question 6.

Answer:

80.02

Explanation:

Given,

97 and 16.98

The subtraction of the given numbers is 80.02

Now let us check the answer by doing an addition

80.02 + 16.98 = 97

Hence the answer is correct.

Question 7.

Answer:

40.76

Explanation:

Given,

42.28 and 1.52

The subtraction of the given numbers is 40.76

Now let us check the answer by doing an addition

40.76 + 1.52 = 42.28

Hence the answer is correct.

Question 8.

Answer:

2.22

Explanation:

Given,

8 and 5.78

The subtraction of the given numbers is 2.22

Now let us check the answer by doing an addition

2.22 + 5.78 = 8

Hence the answer is correct.

Question 9.

36 – 7.3 = _______________

Answer:

28.7

Explanation:

Given,

36 and 7.3

The subtraction of the given numbers is 28.7

Now let us check the answer by doing an addition

28.7 + 7.3 = 36

Hence the answer is correct.

Question 10.

5.6 – 3.5 = _______________

Answer:

2.1

Explanation:

Given,

5.6 – 3.5

The subtraction of the given numbers is 2.1.

Now let us check the answer by doing an addition

2.1 + 3.5 = 5.6

Hence the answer is correct.

Question 11.

19.86 – 9.94 = _______________

Answer:

9.92

Explanation:

Given,

19.86 – 9.94

The subtraction of the given numbers is 9.92.

Now let us check the answer by doing an addition

9.92 + 9.94 = 19.86

Hence the answer is correct.

**Algebra Find each unknown.**

Question 12.

$15.00 – $6.24 = b

b = ______________

Answer:

b = 8.76

Explanation:

Given,

$15.00 – $6.24 = b

Now let us solve the given equation

b = 8.76

Question 13.

8.2 – 6.72 = k

k = ________________

Answer:

k = 1.48

Explanation:

Given,

8.2 – 6.72 = k

Now let us solve the equation

Subtract the numbers

k = 1.48

Question 14.

58.67 – 28.72 = t

t = ________________

Answer:

t = 29.95

Explanation:

Given,

58.67 – 28.72 = t

Now let us solve the equation

Subtract the numbers

t = 29.95

**Problem Solving**

Question 15.

Use the table to find out how many more people there are per square mile in Iowa than in Colorado.

Answer:

There are 10.9 more people there are per square mile in Iowa than in Colorado.

Explanation:

Given,

Population Density in the state of Colorado = 41.5 People per square mile.

Population Density in the state lowa = 52.4 People per square mile.

The difference between them gives us the answer.

52.4 – 41.5 = 10.9 more people.

Question 16.

**Mathematical PRACTICE** Explain to a Friend You decide to buy a hat for $10.95 and a T-shirt for $14.20. How much change will you receive if you pay with a $50 bill? Explain to a friend.

Answer:

$ 25.85.

Explanation:

Given,

A hat for $10.95.

A T-shirt for $14.20.

The bill he paid with a $50 bill.

Total cost to buy a hat and T-shirt is $14.20 + $10.95 = $25.15

$50 – $25.15 = $25.85

Question 17.

Coach Trainer timed his athletes running the 40-yard dash. He used an electronic timer for accuracy. The fastest player on his team ran the 40-yard dash in 4.58 seconds and the slowest time was 5.75 seconds. Find the difference between the fastest and slowest times.

Answer:

1.17 Seconds.

Explanation:

Given,

The fastest player on his team ran the 40-yard dash in 4.58 seconds.

The slowest time was 5.75 seconds.

The difference between the fastest and slowest times is 5.75 – 4.58 = 1.17 seconds.

**HOT Problems**

Question 18.

**Mathematical PRACTICE** Reason Explain how place value could be used to find the difference of 4.23 and 2.75.

Answer:

1.48

Explanation:

Given,

4.23 and 2.75.

Here we have to explain how the place value be used to find the difference of 4.23 and 2.75.

Now we subtract one’s place from one’s place, tenth place from tenth place and hundredth place from hundredth place.

The place value of 4 in 4.23 = unit

The place value of 2 in 4.23 = Tenth place

The place value of 3 in 4.23 = Hundredth

The place value of 2 in 2.75 = One’s

The place value of 7 in 2.75 = Tenth

The place value of 5 in 2.75 = Hundredth

Difference between 4.23 and 2.75 = 4.23 – 2.75 = 1.48

3 is at the hundredth place in 4.23 but less than 5 then it takes to carry one from 2 and then subtract hundredth place 5 in 2.75

Then, we get \(\frac{13}{100}\) – \(\frac{5}{100}\) = \(\frac{8}{100}\)

Now, 2 in 4.23 is in the tenth place and 7 in 2.75 is at the tenth place and 2 is less than 7, and then subtract the tenth place of 2.75 from 4.23

\(\frac{11}{10}\) – \(\frac{7}{10}\) = \(\frac{4}{10}\)

Then giving carry the unit place of 4 in 4.23 is 3.

Subtract unit place of 2.75 from a unit place of 4.23.

3 – 2 = 1

Therefore the difference between 4.23 and 2.75

1 + \(\frac{4}{10}\) – \(\frac{8}{100}\) = 1.48

Question 19.

**Building on the Essential Question** How does place value help me subtract decimals?

Answer:

We have to make sure that the digits are placed based on their place values and that the decimal points are lined up.

### McGraw Hill My Math Grade 5 Chapter 5 Lesson 10 My Homework Answer Key

**Practice**

**Subtract. Use addition to check your answer.**

Question 1.

Answer:

By subtracting the given numbers the answer is 4.94.

Explanation:

Now let us check the answer by using addition.

Add 4.09 + 4.94 = 9.03

Hence the answer is correct.

Question 2.

71.65 – 55.12 = ____________

Answer:

16.53

Explanation:

Now let us check the answer by using addition.

Add 55.12 + 16.53 = 71.65

Hence the answer is correct.

Question 3.

Answer:

$15.69

Explanation:

Now let us check the answer by using addition.

Add 18.94 + 3.25 = $15.69

Hence the answer is correct.

**Problem Solving**

Question 4.

Roberto uses his handheld GPS device to determine that he hikes 21.48 miles in one weekend. The next weekend he hikes 30 miles. How much less did he hike the first weekend than the second weekend?

Answer:

8.52 miles.

Explanation:

He hikes 21.48 miles in one weekend.

The next weekend he hikes 30 miles.

The difference gives us how much less did he hike the first weekend than the second weekend.

30 – 21.48 = 8.52 miles.

Question 5.

Jabir buys 2.74 pounds of dried pinto beans and 4.05 pounds of dried lima beans. What is the difference between the weights of the beans that Jabir buys?

Answer:

1.31 pounds

Explanation:

Given,

Jabir bought = 2.74 pounds of dried pinto beans.

He bought = 4.05 pounds of dried lima beans.

The difference between the weights of the beans that Jabir bought.

4.05 – 2.74 = 1.31 pounds.

Question 6.

Rebekahâ€™s baby brother weighs 7.71 pounds. Her newborn kitten weighs 0.24 pound. How much more does Rebekahâ€™s baby brother weigh than her kitten?

Answer:

7.47 pounds.

Explanation:

Given,

Rebekahâ€™s baby brother weighs 7.71 pounds.

Her newborn kitten weighs 0.24 pounds.

The difference between both weights gives us how much more Rebekahâ€™s baby brother weigh than her kitten.

7.71 – 0.24 = 7.47 pounds.

Question 7.

**Mathematical PRACTICE** Use Number Sense Marshall compares water tanks at the home improvement store. One tank holds 20.2 galIons of water. A second tank holds 28.1 gallons of water. How much more water does the second tank hold than the first tank?

Answer:

7.9

Explanation:

From the given question

No of gallons of water one tank holds = 20.2

No of gallons of water another tank holds = 28.1

Find the difference = 28.1 – 20.2 = 7.9

**Test Practice**

Question 8.

Kamal buys a pen that costs $1.O9andatabletof paper that costs $2.50. How much more does the paper cost than the pen?

(A) $1.31

(B) $1.41

(C) $1.59

(D) $3.59

Answer:

$1.41

Explanation:

Given,

Cost of pen = $1.09

Cost of paper = $2.50

Calculate the difference

2.5 – 1.09 = $1.41