All the solutions provided in **McGraw Hill Math Grade 4 Answer Key PDF Chapter 5 Lesson 2 Estimate Products**Â will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 4 Answer Key Chapter 5 Lesson 2 Estimate Products

**Math in My World**

Example 1

A hamster sleeps 14 hours each day. About how many hours does a hamster sleep in 3 weeks?

There are 21 days in 3 weeks.

So, estimate ___ Ă— ____.

So, a hamster sleeps about ____ hours in days, ___, or 3 weeks.

Since both factors were rounded down, the estimate is less than the actual product.

Answer: A hamster sleeps about 200 hours in a day, 21 or 3 weeks.

Explanation:

Given that,

A hamster sleeps 14 hours each day.

Now, we will find out how many hours a hamster sleeps in 3 weeks.

There are 21 days in 3 weeks.

So, the estimated value is 21 x 14.

The estimation is,

So, a hamster sleeps about 200 hours in days, 21 or 3 weeks.

Since both factors were rounded down, the estimate is less than the actual product.

Example 2

Tonya spends 35 minutes playing at the park each day. About how many minutes does she play at the park Âˇn 38 days?

**Helpful Hint**

If one factor is rounded up and one factor is rounded down, it will not be obvious whether the estimate is greater or less than the actual product.

You need to estimate 38 Ă— ___.

So, Tanya spends about ___ minutes playing at the park.

Since both factors were rounded up, the estimate is ____ than the actual product.

Answer: Tanya spends about 1600 minutes playing at the park.

Since both factors were rounded up, the estimate is greater than the actual product.

Explanation:

Given that,

Tonya spends 35 minutes playing at the park each day.

Now, we will find out how many minutes she plays at the park in 38 days.

First, we need to estimate 38 Ă— 35.

So, Tanya spends about 1600 minutes playing at the park.

Since both factors were rounded up, the estimate is greater than the actual product.

**Talk Math**

Explain how you know if an estimated product is greater than or less than the actual product.

Answer: If the factor is rounded up or the factor is rounded down, then the estimated value is greater or less than the actual product. So, based on the estimated round off we can know the estimated product value is greater than or less than the actual product.

**Guided Practice**

Question 1.

Estimate. Circle whether the estimate is greater than or less than the actual product.

Answer: The estimated value is greater than the actual product.

Explanation:

Given that, the values 57 and 25.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product value of 57 x 25 is

The estimated product value is 1800 and the actual value is 1425.

Hence, the estimated value is greater than the actual value.

**Independent Practice**

**Estimate. Circle whether the estimate is greater than or less than the actual product.**

Question 2.

greater than

less than

Answer: The estimated value is greater than the actual product.

Explanation:

Given that, the values 28 and 25.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product of 28 and 25 is,

The estimated product value is 900 and the actual product value is 700.

Hence, the estimated value is greater than the actual value.

Question 3.

greater than

less than

Answer: The estimated value is less than the actual product.

Explanation:

Given that, the values 43 and 14.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product of 43 and 14 is,

The actual product value is 602 and the estimated value is 400.

Hence, the estimated value is less than the actual product value.

Question 4.

greater than

less than

Answer: The estimated value is greater than the actual product.

Explanation:

Given that, the values 56 and 37.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product value is,

The estimated value is 2400 and the actual value is 2072.

Hence, the estimated value is greater than the actual value.

Question 5.

greater than

less than

Answer: The estimated value is greater than the actual product.

Explanation:

Given that, the values 79 and 55.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product value of 79 and 55 is,

The actual product value is 4345 and the estimated value is 4800.

Hence, the estimated value is greater than the actual value.

Question 6.

greater than

less than

Answer: The estimated value is less than the actual product.

Explanation:

Given that, the values 91 and 64.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product of 91 and 64 is,

The estimated product value is 5400 and the actual product value is 5824.

Hence, the estimated product value is less than the actual product value.

Question 7.

greater than

less than

Answer: The estimated value is less than the actual product.

Explanation:

Given that, the values 94 and 82.

Now, we will find the estimated value which is greater than or less than the actual product.

So, the estimated product is,

The actual product value is,

The estimated product value is 7200 and the actual product value is 7708.

Hence, the estimated value is less than the actual product value.

**Estimate the product.**

Question 8.

23 Ă— 11 = ____

Answer: The estimated product is 200.

Explanation:

Given that the values are 23 and 11.

Now, we will find the estimated product value.

So, the values 23 and 11 are rounded off to the nearest tens.

The estimated value of 23 is 20 and the estimated value of 11 is 10.

The estimated product is,

Hence, the product of the given values is 200.

Question 9.

35 Ă— 37 = ____

Answer: The estimated product is 1600.

Explanation:

Given that the values are 35 and 37.

Now, we will find the estimated product value.

So, the values 35 and 37 are rounded off to the nearest tens.

The estimated value of 35 is 40 and the estimated value of 37 is 40.

The estimated product is,

Therefore, the estimated product is 1600.

Question 10.

48 Ă— 86 = ____

Answer: The estimated product is 4500.

Explanation:

Given that the values are 48 and 86.

Now, we will find the estimated product value.

So, the values 48 and 86 are rounded off to the nearest tens.

The estimated value of 48 is 50 and the estimated value of 86 is 90.

The estimated product is,

Hence, the estimated product is 4500.

Question 11.

53 Ă— 42 = ____

Answer: The estimated product is 2000.

Explanation:

Given that the values are 53 and 42.

Now, we will find the estimated product value.

So, the values 53 and 42 are rounded off to the nearest tens.

The estimated value of 53 is 50 and the estimated value of 42 is 40.

The estimated product is,

Thus, the estimated product is 2000.

Question 12.

67 Ă— 56 = ___

Answer: The estimated product is 4200.

Explanation:

Given that the values are 67 and 56.

Now, we will find the estimated product value.

So, the values 67 and 56 are rounded off to the nearest tens.

The estimated value of 67 is 70 and the estimated value of 56 is 60.

The estimated product is,

Therefore, the estimated product is 4200.

Question 13.

73 Ă— 84 = ____

Answer: The estimated product is 5600.

Explanation:

Given that the values are 73 and 84.

Now, we will find the estimated product value.

So, the values 73 and 84 are rounded off to the nearest tens.

The estimated value of 73 is 70 and the estimated value of 84 is 80.

The estimated product is,

Therefore, the estimated product is 5600.

**Algebra Use mental math to find the unknown number.**

Question 14.

20 Ă— a = 1,200

a = ____

Answer: a = 60

Explanation:

Given that the value is 20 x a = 1200.

Now, we will find the value of a.

So, the values are 20 and 1200.

i.e., 1200/20

Therefore, the value of a is 60.

Question 15.

b Ă— 30 = 900

b = ____

Answer: b = 30

Explanation:

Given that the value is b x 30 = 900.

Now, we will find the value of b.

So, the values are 30 and 900.

i.e., 900/30

Thus, the value of b is 30.

Question 16.

40 Ă— c = 2,400

c = ___

Answer: c = 60

Explanation:

Given that the value is 40 x c = 2400.

Now, we will find the value of c.

So, the values are 40 and 2400.

i.e., 2400/40

Therefore, the value of c is 60.

**Problem Solving**

**Use the information in the table for Exercises 17-18. Write an equation to solve.**

Question 17.

**Mathematical PRACTICE 4 Model Math** Suppose 18 nymph dragonflies of maximum length are laid end to end. About how long would they span?

____ Ă— ___ = ___ mm

Answer: 18 x 55 = 990 mm

Explanation:

Given that,

There are 18 nymph dragonflies.

Now, we will find the maximum length of 18 nymph dragonflies.

In the table given, the maximum length of a nymph is 55 millimeters.

For 18 nymph dragonfiles is 18 x 55,

So, they can span 990 mm.

Question 18.

If 32 average adult dragonflies were laid end to end, about how long would they span?

____ Ă— ___ = ___ mm

Answer: 32 x 74 = 2368 mm

Explanation:

Given that,

There are 32 average adult dragonflies.

Now, we will find the average adult length of 32 dragonflies.

In the table given, the average adult length is 74 millimeters.

For 32 dragonfiles is 32 x 74,

Hence, the average adult length of 32 dragonflies is 2368mm.

**Algebra Write an equation to solve.**

Question 19.

The art room has 15 shelves of paint. Each shelf has 48 cans of paint. About how many cans of paint are there altogether?

____ Ă— ___ = ___ cans of paint

Answer: 15 x 48 = 720 cans of paint.

Explanation:

Given that,

The art room has 15 shelves of paint.

Each shelf has 48 cans of paint.

Now, we will find out how many cans of paint are there altogether.

So, the values are 15 and 48,

Hence, 720 cans of paint are there altogether.

Question 20.

There are 12 millipedes that each measure 16 centimeters long. About how long would they measure if they were laid end to end?

____ Ă— ___ = ___ cm

Answer: 12 Ă— 16 = 192 cm.

Explanation:

As given in the question,

There are 12 millipedes that each measure 16 centimeters long.

Now, we will find out how long would they measure if they were laid end to end.

So, the values are 12 and 16cm,

Therefore, if they were laid end to end the long is 192 cm.

**HOT Problems**

Question 21.

**Mathematical PRACTICE 1 Make a Plan** Identify two factors that have an estimated product of 2,000.

Answer:

The two factors that have an estimated product of 2000 are 52 and 41. The estimated values of 52 and 41 are 50 and 40.

Question 22.

**? Building on the Essential Question** How does an estimated product relate to the actual product? Explain.

Answer:

In order to estimate products, we round the given factors to the required place value. Estimating products helps us to check the reasonableness of an answer. To estimate the product, we first round off the multiplier and the multiplicand to the nearest tens, hundreds, or thousands and then multiply the rounded numbers.

### McGraw Hill My Math Grade 4 Chapter 5 Lesson 2 My Homework Answer Key

**Practice**

**Estimate.**

Question 1.

37 Ă— 22 = ___ Ă— ____

Answer: The estimated value of 37 Ă— 22 = 40 Ă— 20.

Explanation:

Given that, the values are 37 and 22.

Now, we will estimate the given values.

So, the values are rounded off to the nearest tens.

Then the estimated value of 37 is 40 and 22 is 20.

Question 2.

87 Ă— 41 = ____ Ă— ____

Answer: The estimated value of 87 Ă— 41 = 90 Ă— 40.

Explanation:

Given that, the values are 87 and 41.

Now, we will estimate the given values.

So, the given values are rounded off to the nearest tens.

Then the estimated value of 87 is 90 and the estimated value of 41 is 40.

Question 3.

49 Ă— 16 = ___ Ă— ____

Answer: The estimated value of 49 Ă— 16 = 50 Ă— 20.

Explanation:

Given that, the values are 49 and 16.

Now, we will estimate the given values.

So, the values are rounded off to the nearest tens.

Then the estimated value of 49 is 50 and the estimated value of 16 is 20.

Question 4.

25 Ă— 12 = ___ Ă— ____

Answer: The estimated value of 25 Ă— 12 = 30 Ă— 10.

Explanation:

Given that, the values are 25 and 12.

Now, we will estimate the given values.

So, the values are rounded off to the nearest tens.

Then the estimated value of 25 is 30 and the estimated value of 12 is 10.

**Problem Solving**

**Estimate. Tell whether the estimate is greater than or less than the actual product.**

Question 5.

**Mathematical PRACTICE 4 Model Math** A concert ticket costs $23. About how much will tickets cost for a group of 22 people?

Answer: The ticket cost for a group of 22 people is $506.

Explanation:

Given that,

A concert ticket costs $23.

Now, we will find out how much will tickets cost for a group of 22 people.

So, the values are 23 and 22,

Therefore, the ticket cost for a group of 22 people is $506.

Question 6.

There are 32 times students can work in the computer lab during one week If 24 students can work in the computer lab at one time, about how many students can work in the computer lab during one week?

Answer: 768 students can work in the computer lab for one week.

Explanation:

As given in the question,

There are 32 times students can work in the computer lab in one week.

If 24 students can work in the computer lab at one time,

Then find out how many students can work in the computer lab for one week.

So, the values are 32 and 24,

Hence, 768 students can work on the computer for one week.

**Algebra Write an equation to solve.**

Question 7.

Ramona creates 16 paintings each month. About how many paintings will she create in 3 years?

_____ Ă— ____ = paintings

Answer: 16 x 36 = 576 paintings.

In 3 years, she creates 576 paintings.

Explanation:

Given that,

Ramona creates 16 paintings each month.

Now, we will find out how many paintings will she create in 3 years.

We know that 1 year = 12 months.

So, 3 years = 36 months.

Then 3 years of paintings are,

Therefore, 576 paintings will she created in 3 years.

Question 8.

Michael averages 12 points in each basketball game. About how many points will he score in 12 games?

_____ Ă— ____ = points

Answer: 12 Ă— 12 = 144 points

In 12 games he scored 144 points.

Explanation:

As given in the question,

Michael averages 12 points in each basketball game.

Now, we will find out how many points will he score in 12 games.

So, the values are 12 and 12,

Hence, in 12 games he scored 144 points.

**Test Practice**

Question 9.

Theater tickets cost $48 per person. About how much money would ticket for 35 people cost?

A. $2,000

B. $1,500

C. $1,200

D. $200

Answer: Option C

Explanation:

Given that,

Theater tickets cost $48 per person.

Now, we will find out how much money would ticket for 35 people cost.

So, the values are 48 and 35,

For 35 people the ticket cost is $1680.

But based on the given option, option A is correct. Because the remaining option’s value is less than 1600 only option A value is greater than 1600.

Hence, option A is correct.