All the solutions provided inÂ **McGraw Hill My Math Grade 4 Answer Key PDF Chapter 12 Lesson 3 Metric Units of Mass **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 4 Answer Key Chapter 12 Lesson 3 Metric Units of Mass

Mass is the amount of matter an object has. The mass of an object is not affected by gravity. However, an objectâ€™s weight differs depending on gravity.

gram (g)

The mass of a penny is about 1 gram.

kIlogram (kg)

The mass of six medium apples is about 1 kilogram.

1,000 grams (g) = 1 kilogram (kg)

**Math in My World**

**Example 1**

Which is the more reasonable estimate for the mass of the laptop, 2 grams or 2 kilograms?

Use logic to estimate the mass.

So, _________________ is the more reasonable estimate.

Answer: So, 2 kilograms is the more reasonable estimate.

Explanation: Given that

Now, we will estimate the mass of the laptop.

The given values are 2 grams and 2 kilograms which is the more reasonable estimate.

The 2 grams is too small. The laptop is a large object. So, the best estimate is 2 kilograms.

Hence, the best estimated mass of the laptop is 2 kilograms.

**Example 2**

Is it more reasonable to say that a rabbit’s mass is 3 grams or 3 kilograms?

So, _________________ is the more reasonable estimate.

Answer: So, 3 kilograms is the more reasonable estimate.

Explanation: Given that figure

Now, we will estimate the mass of the rabbit.

The given values are 3 grams and 3 kilograms which is the more reasonable estimate.

The 3 grams is too small. The rabbits has a some large mass. So, the best estimate is 3 kilograms.

Hence, the best estimated mass of the rabbits is 3 kilograms.

**Talk Math**

Explain the difference between weight and mass.

Answer: The difference between mass and weight is, mass is the measure of the amount of matter in a body. It is denoted by m or M. The weight is the measure of the amount of force acting on a mass due to the acceleration due to gravity.

**Guided Practice**

**Circle the more reasonable estimate for each mass.**

Question 1.

25 grams

25 kilograms

Answer: The best estimate mass of the cap is 25 grams.

Explanation: Given the figure

Now, we will estimate the mass of the cap.

The given values are 25 grams and 25 kilograms which is the more reasonable estimate.

The 25 kilograms is very large. The cap is a small object. So, the best estimate is 25 grams.

Hence, the best estimated mass of the cap is 25 grams.

Question 2.

450 grams

450 kilograms

Answer: The estimate mass of white bear is 450 kilograms.

Explanation: Given that,

Now, we will estimate the mass of the white bear.

The given values are 450 grams and 450 kilograms which is the more reasonable estimate.

The 450 grams is too small. The white bear has some high mass . So, the best estimate is 450 kilograms.

Hence, the best estimated mass of the white bear is 450 kilograms.

**Independent Practice**

**Circle the more reasonable estimate for each mass.**

Question 3.

8 grams

8 kilograms

Answer: The estimate mass of paper roll is 8 grams.

Explanation: Given the figure

Now, we will estimate the mass of the paper roll.

The given values are 8 grams and 8 kilograms which is the more reasonable estimate.

The 8 kilograms is too large mass. The paper roll is a small object. So, the best estimate is 8 grams.

Hence, the best estimated mass of the paper roll is 8 grams.

Question 4.

100 grams

100 kilograms

Answer: The estimate mass of crayons is 100 grams.

Explanation: Given the figure,

Now, we will estimate the mass of the crayons.

The given values are 100 grams and 100 kilograms which is the more reasonable estimate.

The 100 kilograms is too large. The crayons are small object. So, the best estimate is 100 grams.

Hence, the best estimated mass of the crayons is 100 grams.

Question 5.

25 grams

25 kilograms

Answer: The estimate mass of cool drink box 25 kilograms.

Explanation: Given the figure,

Now, we will estimate the mass of the cool drink box.

The given values are 25 grams and 25 kilograms which is the more reasonable estimate.

The 25 kilograms is too small. The cool drink box is large object. So, the best estimate isÂ 25 kilograms.

Hence, the best estimated mass of the cool drink box is 25 kilograms.

Question 6.

20 grams

20 kilograms

Answer:The estimate mass of ball is 20 grams.

Explanation: Given the figure,

Now, we will estimate the mass of the ball.

The given values are 20 grams and 20 kilograms which is the more reasonable estimate.

The 20 kilograms is too large. The ball is a small object. So, the best estimate is 20 grams.

Hence, the best estimated mass of the ball is 20 grams.

Question 7.

30 grams

30 kilograms

Answer: The estimate mass of the given box is 30 kilograms.

Explanation: Given the figure

Now, we will estimate the mass of the given box.

The given values are 30 grams and 30 kilograms which is the more reasonable estimate.

The 30 grams is too small. The given box is a large object. So, the best estimate is 30 kilograms.

Hence, the best estimated mass of the given box is 30 kilograms.

Question 8.

50 grams

50 kilograms

Answer: The estimate mass of table is 50 kilograms.

Explanation: Given the figure,

Now, we will estimate the mass of the table.

The given values are 50 grams and 50 kilograms which is the more reasonable estimate.

The 50 grams is too small. The table is large object. So, the best estimate is 50 kilograms.

Hence, the best estimated mass of the box is 50 kilograms.

Question 9.

The table lists items that can be found in the classroom. Estimate the mass of each object. Record your estimates in the table.

Answer: The below is the table which contains a items that can be found in the classroom. We will estimate the mass of each object.

**Problem Solving**

Question 10.

Tyler bought a large bag of peanuts at a baseball game. Is it more reasonable to say that the mass of the peanuts is 1 gram or 1 kilogram?

Answer: Yes, it reasonable to say the mass of the peanuts is 1 kilogram.

Explanation: Given that,

Tyler bought a large bag of peanuts at a baseball game

Now, we will estimate the mass of the peanuts.

The given values are 1 grams and 1 kilograms which is the more reasonable estimate.

The 1 grams is too small. The bag of peanuts has large mass. So, the best estimate is 1 kilogram.

Hence, the best estimate mass of the peanuts is 1 kilogram.

Question 11.

**Mathematical PRACTICE** Explain to a Friend Alicia is buying 6 oranges that cost $1 per kilogram. Is it reasonable to say that the cost of the oranges will be greater than $6? Explain to a friend.

Answer: No, its not reasonable. The cost of the oranges would be less than 6kg. Since, 6 kg oranges costs are $6, 6 oranges would be less than $6.

**HOT Problems**

Question 12.

**Mathematical PRACTICE** Model Math List five classroom objects that have a mass greater than 1 kilogram.

Answer: The five classroom objects that have a mass greater than 1 kilogram is Desks, Benches, Chair, Geometry Box, School Bag with books.

Question 13.

**Mathematical PRACTICE** Reason Items with greater mass cost more money to ship. Would it cost more to ship a box of 8 markers or a box of 20 paper clips? Explain.

Answer: A box 8 markers would be cost more to ship. Beacuse 8 markers have a greater mass than 20 paper clips.

Explanation: Given that,

A box has 8 markers and 20 paper clips.

The number of paper clips are more and number of markers are less.

But the mass of marker is high than the paper clip, because of the paper clip is too small compared to size of the marker.

Therefore, the 8 markers have greater mass than 20 paper clips.

Question 14.

**Building on the Essential Question** Name a real-world example of something that has a mass that can be measured with a metric unit.

Answer: The mass that can be measured with a ametric unit is, when riding an elevator i can estimate the total kilograms loaded in the elevator to make sure that it is under weight limit.

### McGraw Hill My Math Grade 4 Chapter 12 Lesson 3 My Homework Answer Key

**Practice**

**Circle the more reasonable estimate for each mass.**

Question 1.

1,500 grams

1,500 kilograms

Answer: The estimate mass of the school bus is 1500 kilograms.

Explanation: Given the figure

Now, we will estimate the mass of the school bus.

The given values are 1500 grams and 1500 kilograms which is the more reasonable estimate.

The 1500 grams is too small. The school bus is a large object. So, the best estimate is 1500 kilograms.

Hence, the best estimated mass of the school bus is 1500 kilograms.

Question 2.

5 grams

5 kilograms

Answer: The estimate mass of the ball is 5 grams.

Explanation: Given the figure

Now, we will estimate the mass of the ball.

The given values are 5 grams and 5 kilograms which is the more reasonable estimate.

The 5 kilograms is too large. The ball is a small object. So, the best estimate is 5 grams.

Hence, the best estimated mass of the ball is 5 grams.

Question 3.

3 grams

3 kilograms

Answer: The estimate mass of the chocolate is 3 grams.

Explanation: Given the figure

Now, we will estimate the mass of the chocolate.

The given values are 3 grams and 3 kilograms which is the more reasonable estimate.

The 3 kilograms is too large. The chocolate is a small object. So, the best estimate is 3 grams.

Hence, the best estimated mass of the chocolate is 3 grams.

Question 4.

14 grams

14 kilograms

Answer: The estimate mass of the dog is 14 kilograms.

Explanation: Given the figure

Now, we will estimate the mass of the dog.

The given values are 14 grams and 14 kilograms which is the more reasonable estimate.

The 14 grams is too small. The dog has some large mass. So, the best estimate is 14 kilograms.

Hence, the best estimate mass of the dog is 14 kilograms.

**Complete the table by writing a reasonable unit of mass, grams or kilograms, for each object.**

Answer:Â The unit mass of each given object is,

**Problem Solving**

Question 10.

The mass of a pen cap is 1 unit What metric unit, gram or kilogram, was used to measure the mass of the pen cap?

Answer: The metric unit used to measure the mass of the pen cap is gram. The gram is much smaller than kilogram and a kilogram is too big to fit in a pen cap. So, the metric unit of pen cap is gram.

Question 11.

**Mathematical PRACTICE** Explain to a Friend Julio is buying a carton of blueberries that has a mass of 100 grams. Is it reasonable to say that there are 250 blueberries in the carton? Explain.

Answer: No, its not reasonable to sayÂ that there are 250 blueberries in the carton because the average weight of the blueberry in the carton does not make sense.

The average weight of the blueberry in the cartoon is 100/250 = 0.4

The normal average weight of blueberry is 0.66 to 1.5 gram.

So, its not reasonable to say that there are 250 blueberries in the carton.

**Vocabulary Check**

Match each vocabulary term to its definition or example.

Answer:Â The given terms definitions are,

**Test Practice**

Question 15.

Which is a reasonable estimate for the mass of a toothbrush?

(A) 2 grams

(B) 20 grams

(C) 200 grams

(D) 2,000 grams

Answer: Option B

Explanation: Given the data,

Now, we will estimate the mass of the toothbrush.

Based on the given options, option B 20 grams is correct.

The 2 grams is too small. The 200 grams and 2000 grams is very large.

Hence, the best estimate mass of the toothbrushÂ is 20grams.