All the solutions provided in McGraw Hill My Math Grade 5 Answer Key PDF Chapter 5 Lesson 5 Add Decimals Using Models will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 5 Answer Key Chapter 5 Lesson 5 Add Decimals Using Models
Build It
Find 1.2 + 0.7. Use models to find the sum.
1. Use 10-by-10 grids to model 1.2.
To show 1.2, shade one whole 10-by-10 grid and two-tenths of a second grid.
Two-tenths is equal to _____________ small squares.
Answer:
Two-tenths is equal to 20 small squares.
2. Model 0.7
To show 0.7, shade seven-tenths of the second grid using a different color.
Answer:
3. Add.
How many ones are there? ____________
How many tenths are there? _____________
So, 1.2 + 0.7 = ___________.
Check Use estimation to check for reasonableness.
1 + 1 = 2 and ___________ ≈ 2
Answer:
There are one one’s.
There are nine-tenths.
So, 1.2 + 0.7 = 1.9.
Check Use estimation to check for reasonableness.
1 + 1 = 2 and 1.9 ≈ 2
Try It
Find 1.08 + 0.45. Use models.
1. Model 1.08.
To show 1.08, shade one whole 10-by-10 grid and eight-hundredths of a second grid.
Eight-hundredths is equal to ___________ small squares.
Answer:
Eight-hundredths is equal to 80 small squares.
2. Model 0.45
To show 0.45, shade forty-five hundredths of the second grid using a different color.
Helpful Hint
1 one, 5 tenths, and 3 hundredths is equal to 1.53.
3. Add.
How many ones are there? _____________
How many tenths are there? _____________
How many hundredths are there? _____________
So, 1.08 + 0.45 = _____________.
Check Use estimation to check for reasonableness.
1 + 0.5 = 1.5 and ______________ ≈ 1.5
Answer:
There are one one’s.
There are five-tenths.
There are 3 hundredths.
so, 1.08 + 0.45 = 1.53
Check Use estimation to check for reasonableness.
1 + 0.5 = 1.5 and 1.53 ≈ 1.5
Talk About It
Question 1.
Explain how to use grid paper to model 0.2 and 0.02. Describe any differences.
Answer:
Check for the grid Two tenths for 0.2 and Two hundredths for 0.02.
Therefore there will be 20 small squares shaded for 0.2 and 2 squares are shaded for 0.02.
Question 2.
Mathematical PRACTICE Model Math What decimal is modeled by a 10-by-10 grid with 82 small squares shaded? Explain.
Answer:
The decimal that is modeled by a 10-by-10 grid with 82 small squares shaded is 0.82.
Explanation:
Eighty – Two-hundredths is equal to 82 small squares.
Practice It
Add. Shade the decimal models.
Question 3.
2.46 + 1.13 = _____________
Answer:
3.59
Explanation:
The addition of the two given numbers is 2.46 + 1.13 = 3.59.
Question 4.
2.05 + 1.87 = ______________
Answer:
3.92
Explanation:
The addition of the two given numbers is 2.46 + 1.13 = 3.92.
Question 5.
2.91 + 1.8 = ______________
Answer:
4.71
Explanation:
The addition of the two given numbers is 2.91 + 1.8 = 4.71.
Question 6.
1.34+ 1.15 = _______________
Answer:
2.49
Explanation:
The addition of the two given numbers is 1.34+ 1.15 = 2.49.
Question 7.
1.74 + 0.36 = _______________
Answer:
2.1
Explanation:
The addition of the two given numbers is 1.74 + 0.36 = 2.1
Question 8.
2.05 + 1.12 = ________________
Answer:
3.17
Explanation:
The addition of the two given numbers is 2.05 + 1.12 = 3.17
Apply It
Question 9.
The length of a nickel is 2.1 centimeters. What is the combined length of two nickels lying side by side? Use decimal models to find the sum.
Answer:
4.2 cm.
Explanation:
Given,
The length of a nickel is 2.1 centimeters.
The length of two nickels lying side by side is 2.1 + 2.1 = 4.2 cm.
Question 10.
Shawn used 2.5 pounds of ground beef to make hamburgers for a cookout. He also used 1.32 pounds of ground beef to make spaghetti. How many total pounds of ground beef did Shawn use? Use decimal models to find the sum.
Answer:
3.82 pounds.
Explanation:
Shawn used 2.5 pounds of ground beef.
He also used 1.32 pounds of ground beef
Total = 2.5 + 1.32 = 3.82 pounds.
Question 11.
Mathematical PRACTICE Use Math Tools Marvin bought 0.6 pound of almonds and 1.73 pounds of cashews at the store. What is the total weight of the almonds and cashews he bought? Use decimal models to find the sum.
Answer:
2.33 pounds.
Explanation:
Given,
Marvin bought 0.6 pounds of almonds.
1.73 pounds of cashews at the store
The total weight of the almonds and cashews he bought is 0.6 + 1.73 = 2.33 pounds.
Question 12.
Mathematical PRACTICE Find the Error Melanie used decimal models to add 1.03 and 0.4. Her result was 1.07. Shade the models to find the correct sum.
The correct sum is ____________.
Answer:
The correct sum is 1.43.
Explanation:
Write About It
Question 13.
How can I use decimal models to add decimals?
Answer:
To add the decimals we have to build base ten blocks.
Regroup when the sum of any place value is 10 or more.
Explanation:
Let us take an example to understand decimal models to add decimals.
The numbers are 0.63 and 0.51.
By adding them the answer is 1.14.
McGraw Hill My Math Grade 5 Chapter 5 Lesson 5 My Homework Answer Key
Practice
Add. Shade the decimal models.
Question 1.
0.51 + 0.63 = _____________
Answer:
0.51 + 0.63 = 1.14
Explanation:
Question 2.
1.93 + 1.13 = _____________
Answer:
1.93 + 1.13 = 3.06
Explanation:
Problem Solving
Question 3.
Norah wants to download two different applications on her cell phone. One used 2.42 megabytes and the other one used 1.76 megabytes. How many total megabytes of memory will Norah use to download the two applications? Draw decimals models to find the sum.
Answer:
4.18 megabytes
Explanation:
Given,
Nora used her cellphone to download one application is 2.42 megabytes.
Nora used her cellphone to download another application is 1.76 megabytes.
The total megabytes of memory will Norah use to download the two applications is 2.42 + 1.76 = 4.18 megabytes.
Question 4.
Mathematical PRACTICE Model Math Write a real-world problem that can be solved by adding 1.39 and 2.45 using decimal models. Then solve.
Answer:
The cost of a drink is $ 1.39. The cost of a bag of chocolates is $2.45. Then what is the total cost for both items?
The answer to the above question is $3.84.
1.39 + 2.45 = $3.84.
Explanation:
Question 5.
Dorian feeds his dog 7.5 pounds of food in a week. He feeds his cat 3.75 pounds of food in a week. How many total pounds of food do his pets eat in a week? Draw decimal models to find the sum.
Answer:
11.25 pounds
Explanation:
Given,
Dorian feeds his dog = 7.5 pounds
He feeds his cat = 3.75 pounds
Total pounds of food do his pets eat in a week = 7.5 + 3.75 = 11.25 pounds.