All the solutions provided in McGraw Hill My Math Grade 5 Answer Key PDF Chapter 6 Lesson 5 Multiply Decimals will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 5 Answer Key Chapter 6 Lesson 5 Multiply Decimals
Math in My World
Example 1
Nina is buying peanuts in bulk. The peanuts cost $0.75 for each pound. She purchased 2.1 pounds of peanuts. How much will Nina pay? Round to the nearest cent.
Find $0.75 × 2.1.
Estimate $0.75 × 2.1 → ___________ × ____________ or ___________
1. Multiply as with whole numbers.
2. Count the decimal places.
3. Since 2 + 1 = 3, count 3 decimal places from the right to place the decimal point.
4. Round to the nearest cent.
$1,575 → ___________
So, Nina will need to pay __________.
Check $2 ≈ ___________
Answer:
$0.75 × 2.1 = 1.575
Estimate $0.75 × 2.1 → 1 × 2 or 2
Since 2 + 1 = 3, count 3 decimal places from the right to place the decimal point
Round to the nearest cent.
$1,575 → $1,58
So, Nina will need to pay $1.58.
Check $2 ≈ $1.58
Explanation:
The peanuts cost $0.75 for each pound.
She purchased 2.1 pounds of peanuts.
Total amount will Nina pay $0.75 x 2.1 = $1.575
Round to the nearest cent as $1.58.
Example 2
Demarcus is buying a new guitar pick that costs $0.50. The sales tax is found by multiplying the cost of the guitar pick by 0.06. What is the cost of the sales tax for the pick?
Find $0.50 × 0.06.
Estimate $0.50 × 0.06 → $1 × 0 = $0
1. Multiply as with whole numbers.
2. Count the decimal places.
3. Since 2 + 2 = 4, count 4 decimal places from the right. Annex a zero to place the decimal point.
So, 0.50 × 0.06 = ___________.
The sales tax is ___________.
Check The product, ___________, is close to the estimate, ____________.
The answer is reasonable.
Answer:
1. Multiply as with whole numbers.
0 x 0 = 0
2. Count the decimal places.
Two places.
3. Since 2 + 2 = 4, count 4 decimal places from the right. Annex a zero to place the decimal point.
So, 0.50 × 0.06 = 3.
The sales tax is $3.
Check The product, 3.0000, is close to the estimate, 3.
The answer is reasonable.
Explanation:
Demarcus ¡s buying a new guitar pick that costs $0.50.
The sales tax is found by multiplying the cost of the guitar pick by 0.06.
The cost of the sales tax for the pick,
$0.50 × 0.06 = 3
Talk Math
Describe a multiplication problem in which the product is between 0.005 and 1.
Answer:
0.1
Explanation:
0.1 x 1 = 0.1
by multiplying 1 x 1 = 1
1 x 0.005 = 0.005
the answer must be between 1 to 0.005
1 to be multiplied by minimum one decimal and maximum 3 decimal,
or divided by 1000 to get quotient in 0.005.
Guided Practice
Multiply.
Question 1.
0.6 × 0.8 = ____________
Answer:
0.48
Explanation:
Ignore the decimals and multiply as with whole numbers.
6 x 8 = 48
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.6 x 0.8 = 0.48
Question 2.
1.7 × 2.4 = _____________
Answer:
4.08
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 1.7 x 2.4 = 4.08
Question 3.
0.9 × 3.8 = ______________
Answer:
3.42
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.9 × 3.8 = 3.42
Independent Practice
Multiply. Check for reasonableness.
Question 4.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.96 x 7.1 = 6.816
Question 5.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 3.65 x 2.6 = 9.490
Question 6.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.07 x 5.2 = 0.364
Question 7.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 2.78 x 0.8 = 2.224
Question 8.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 2 = 2, count 4 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.35 x 0.15 = 0.0525
Question 9.
Answer:
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 3.24 x 6.4 = 20.736
Question 10.
0.9 × 0.3 = _____________
Answer:
0.27
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.9 × 0.3 = 0.27
Question 11.
1.6 × 3.2 = ______________
Answer:
5.12
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 1.6 × 3.2 = 5.12
Question 12.
0.5 × 6.7 = _____________
Answer:
3.35
Explanation:
Ignore the decimals and multiply as with whole numbers.
Count the decimal points in the given sum,
Since 1 + 1 = 2, count 2 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.5 × 6.7 = 3.35
Algebra Find each unknown.
Question 13.
0.81 × 7.3 = b
b = _______________
Answer:
b = 5.913
Explanation:
Question 14.
5.6 × 3.9 = p
p = _______________
Answer:
p = 21.84
Explanation:
Question 15.
1.2 × 0.05 = g
g = _______________
Answer:
g = 0.06
Explanation:
Problem Solving
Question 16.
A nutrition label says that one serving out of a bag of chips has 3.7 grams of fat. How many grams of fat are there in 2.5 servings?
Answer:
9.25 grams.
Explanation:
One serving out of a bag of chips has 3.7 grams of fat.
No. of grams of fat in 2.5 servings,
2.5 x 3.7 = 9.25 grams.
Question 17.
Apples cost $0.98 per pound. How much would it cost to purchase 5.5 pounds of apples?
Answer:
$5.39
Explanation:
Apples cost $0.98 per pound.
Cost of 5.5 pounds of apples,
0.98 x 5.5 = $5.39
Question 18.
The average honeybee can travel 10.5 feet per second. How many feet can the honeybee travel in 3.7 seconds?
Answer:
38.85 feet.
Explanation:
The average honeybee can travel 10.5 feet per second.
No. of feet can the honeybee travel in 3.7 seconds,
10.5 x 3.7 = 38.85 feet.
Question 19.
Mathematical PRACTICE Be Precise Jocelyn’s swimming pool is shown. Find the area of the swimming pool.
Answer:
110.625 sq ft.
Explanation:
Area of rectangle = length x width
length = 7.5 feet; width = 14.75 feet.
A = 7.5 x 14.75 = 110.625 sq ft.
HOT Problems
Question 20.
Mathematical PRACTICE Model Math Write a multiplication problem using two decimals that has a product greater than 0.1 but less than 0.2.
Answer:
Richard paints a picture on a rectangular canvas that is 0.2 feet by 0.6 feet. What is the area of Richard’s painting?
Explanation:
Area of rectangle = length x width
Richard paints a picture on a rectangular canvas that is 0.2 feet by 0.6 feet.
A = 0.2 x 0.6 = 0.12 square feet.
we have two decimals 0.2 and 0.6 the product is 0.12 between 0.1 but less than 0.2
Question 21.
Building on the Essential Question How is multiplying decimals different from multiplying whole numbers?
Answer:
The only difference between multiplying whole numbers and multiplying decimals is that we have the added step of moving the decimal point after performing the multiplication when multiplying decimals.
Explanation:
For example:
48 x 3 = 144
When we multiply the whole number with the other whole number,
the product is also whole number.
4.8 x 3 = 14.4
multiplying decimals is that we have the added step of moving the decimal point after performing the multiplication when multiplying decimals.
McGraw Hill My Math Grade 5 Chapter 6 Lesson 5 My Homework Answer Key
Practice
Multiply. Check for reasonableness.
Question 1.
Answer:
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 2 = 4, count 4 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.28 × 0.03 = 0.0084
Question 2.
Answer:
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 2 = 4, count 4 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.11 × 0.91 = 0.1001
Question 3.
Answer:
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 5.14 × 0.4 = 2.056
Question 4.
0.98 × 0.23 = _____________
Answer:
0.2254
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 2 = 4, count 4 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.98 × 0.23 = 0.2254
Question 5.
0.52 × 0.48 = _____________
Answer:
0.2496
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 2 = 4, count 4 decimal places from the right.
Annex a zero to place the decimal point.
So, 0.52 × 0.48 = 0.2496
Question 6.
6.34 × 0.7 = _____________
Answer:
4.438
Explanation:
Multiply as with whole numbers as shown above.
Count the decimal points in the given sum,
Since 2 + 1 = 3, count 3 decimal places from the right.
Annex a zero to place the decimal point.
So, 6.34 × 0.7 = 4.438
Algebra Find each unknown.
Question 7.
0.47 × 0.18 = t
t = ___________
Answer:
t = 0.0846
Explanation:
Question 8.
4.15 × 6.3 = x
x = ___________
Answer:
x = 26.145
Explanation:
Question 9.
0.9 × 1.02 = w
w = ___________
Answer:
w = 0.918
Explanation:
Problem Solving
Question 10.
Tamara recycles 29.5 pounds of aluminum cans at a recycling center that pays $0.26 per pound. How much does Tamara receive for the cans?
Answer:
$7.67
Explanation:
Tamara recycles 29.5 pounds of aluminum cans at a recycling center.
Cost of each pound is $0.26.
Total amount Tamara receive for the cans,
29.5 x $0.26 = $7.67
Question 11.
Wes measures the floor area of his rectangular living room to replace the carpet with tiles. The room is 12.4 feet long and 9.8 feet wide. How many square feet of tile will Wes need?
Answer:
121.52 square feet.
Explanation:
Area of a rectangle = length x width
The room is 12.4 feet long and 9.8 feet wide.
A = 12.4 x 9.8 = 121.52 square feet.
Question 12.
Mathematical PRACTICE Use Number Sense Lenora buys 3.7 pounds of potatoes that cost $0.29 per pound. How much does Lenora pay for the potatoes? Round to the nearest cent.
Answer:
$1.073 or $2
Explanation:
Lenora buys 3.7 pounds of potatoes that cost $0.29 per pound.
Total amount Lenora pay for the potatoes 3.7 x $0.29 = $1.073
Test Practice
Question 13.
Mikayla is buying deli meat and cheese for sandwiches for a family reunion. How much will she spend on 4.5 pounds of ham and 3.5 pounds of cheese?
(A) $7.39
(B) $13.27
(C) $20.66
(D) $33.92
Answer:
Option(D)
Explanation:
Ham per pound = $4.59; Cheese = $ 3.79
She spends on 4.5 pounds of ham and 3.5 pounds of cheese,
Cost of 4.5 pounds of ham = $4.5 x $4.59 = $20.655
Cost of 3.5 pounds of cheese = $3.79 x $3.5 = $13.265
Total amount she spends on ham and cheese = $33.92