All the solutions provided in McGraw Hill My Math Grade 5 Answer Key PDF Chapter 5 Lesson 8 Subtract Decimals Using Base-Ten Blocks will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 5 Answer Key Chapter 5 Lesson 8 Subtract Decimals Using Base-Ten Blocks
Build It
Find 1.8 – 0.4. Use base-ten blocks.
1. Model 1.8.
2. Take 0.4, or four tenths, away.
Count the remaining base-ten blocks. Draw the result.
How many ones are left? _____________
Answer:
There are 1 ones left.
How many tenths are left? ____________
Answer:
There are 4 tenths left.
So, 1.8 – 0.4 = 1.4.
/
Check Use addition to check your answer.
____________ + 0.4 = 1.8
Answer:
1.4+0.4 = 1.8.
Explanation:
To check the answer we will add 1.4+0.4 which is 1.8. So the answer is correct.
Try It
Find 2.25 – 0.75. Use base-ten blocks.
1. Model 2.25.
2. Subtract 0.75. Count the remaining base-ten blocks. Draw the result.
To take away 0.75, take away 7 tenths and 5 hundredths. But you cannot subtract 7 tenths from 2 tenths. So, regroup the ones block as 10 tenths. Then subtract.
How many ones are left? ______________
Answer:
There are 1 ones left.
How many tenths are left? ______________
Answer:
There are 6 tenths are left.
How many hundredths are left? ______________
Answer:
There are 5 hundredths are left.
So, 2.25 – 0.75 = 1.5.
Check Use addition to check your answer.
__________ + 0.75 = 2.25
Answer:
1.5+0.75 = 2.25.
Explanation:
To check the answer we will add 1.5+0.75 which is 2.25. So the answer is correct.
Talk About It
Question 1.
Mathematical PRACTICE Explain to a Friend Explain to a friend or classmate when you should regroup when subtracting decimals with base-ten blocks.
Answer:
We will do regrouping when the minuend is smaller than the subtrahend while subtracting decimals with the base-ten blocks.
Question 2.
How many tenths blocks will you need to subtract 0.35 from 1.21 Explain.
Answer:
We have subtracted 3 tenths blocks.
Explanation:
Here, we need to subtract 0.35 from 1.21. So 1.21-0.35 is 0.86, we have subtracted 3 tenths blocks from 11 blocks of tenths. As we have bought a carry from ones.
Practice It
Subtract. Use base-ten blocks. Draw each result in the table.
Question 3.
0.8 – 0.3 = _____________
Answer:
0.8 – 0.3 = 0.5.
Explanation:
Given the equation is 0.8 – 0.3 which is 0.5.
Question 4.
2.8 – 0.7 = _____________
Answer:
2.8 – 0.7 = 2.1.
Explanation:
Given the equation is 2.8 – 0.7 which is 2.1.
Question 5.
1.43 – 0.31 = _____________
Answer:
1.43 – 0.31 = 1.12.
Explanation:
Given the equation is 1.43 – 0.31 which is 1.12.
Question 6.
2.17 – 1.9 = _____________
Answer:
2.17 – 1.9 = 0.27.
Explanation:
Given the equation is 2.17 – 1.9 which is 0.27
Question 7.
2.52 – 1.48 = _____________
Answer:
2.52 – 1.48 = 1.04.
Explanation:
Given the equation is 2.52 – 1.48 which is 1.04.
Question 8.
3.85 – 2.19 = _____________
Answer:
3.85 – 2.19 = 1.66.
Explanation:
Given the equation is 3.85 – 2.19 which is 1.66.
Apply It
Question 9.
Vaughn’s MP3 player had a memory of 2.5 gigabytes. He has used 1.76 gigabytes of memory. How much memory space does Vaughn’s MP3 player have left? Use base-ten blocks to help you solve.
Answer:
The space left in Vaughn’s MP3 player is 0.74.
Explanation:
Given that Vaughn’s MP3 player had a memory of 2.5 gigabytes and he has used 1.76 gigabytes of memory. So the space left in Vaughn’s MP3 player is 2.5-1.76 which is 0.74.
Question 10.
Yolanda cut a piece of wood that was 1.6 feet long from a 3.25-foot piece of wood. How long is the remaining piece of wood? Use base-ten blocks to help you solve.
Answer:
The length of the remaining piece of wood is 1.65 feet.
Explanation:
Given that Yolanda cut a piece of wood that was 1.6 feet long from a 3.25-foot piece of wood. So the length of the remaining piece of wood is 3.25-1.6 which is 1.65 feet.
Question 11.
Mathematical PRACTICE Model Math Write a real-world problem that can be solved using the base-ten blocks below.
Answer:
Marcus bought chocolates for $2.32 and chips for $0.99. How much money does he have still?
The answer is $1.33.
Explanation:
Given,
Marcus bought chocolates for $2.32
Chips for $0.99
We need to find out how much money he has still.
Subtract the given numbers to find the answer.
2.32 – 0.99 = $1.33
Write About It
Question 12.
How can I use base-ten blocks to subtract decimals?
Answer:
1. At first stack the given numbers and subtract them.
2. Keep the decimal point straight.
3. If needed we have to regroup the numbers or subtract.
4. Just like the whole numbers we should never mix up the place values when adding or subtracting.
Explanation:
Let us take an example to understand the process.
McGraw Hill My Math Grade 5 Chapter 5 Lesson 8 My Homework Answer Key
Practice
Subtract. Use base-ten blocks. Draw each result in the table.
Question 1.
1.3 – 0.28 = ______________
Answer:
1.3 – 0.28 = 1.02.
Explanation:
Given the equation is 1.3 – 0.28 which is 1.02.
Question 2.
3.52 – 1.39 = ______________
Answer:
3.52 – 1.39 = 2.13.
Explanation:
Given the equation is 3.52 – 1.39 which is 2.13.
Problem Solving
Question 3.
Mathematical PRACTICE Model Math The temperature at 6:00 A.M. was 0.8°F. By 3:00 P.M., the temperature had increased to 2.4°F. Find the difference between the two temperatures. Draw models to find the difference.
Answer:
The difference between the two temperatures is 2.4-08 which is 1.6 °F.
Explanation:
Given that the temperature at 6:00 A.M. was 0.8°F. By 3:00 P.M., the temperature had increased to 2.4°F. The difference between the two temperatures is 2.4-08 which is 1.6 °F.
Question 4.
Melissa calculated that she can swim 3.6 miles per hour. Avery calculated her swimming speed to be 2.8 miles per hour. How much faster was Melissa’s swimming speed? Draw models to find the difference.
Answer:
Melissa swims 0.8 miles faster than Avery.
Explanation:
Given, Melissa calculated that she can swim 3.6 miles per hour and Avery calculated her swimming speed to be 2.8 miles per hour. So Melissa’s swimming is 3.6-2.8 which is 0.8 miles faster than Avery’s.
Question 5.
Monica paid for a milkshake using $3. If the milkshake costs $2.67, how much change will she receive? Draw models to find the difference.
Answer:
The change she will receive is $0.33.
Explanation:
Given Monica paid for a milkshake using $3 and if the milkshake costs $2.67. So the change she will receive is $3-$2.67 which is $0.33.
