All the solutions provided in **McGraw Hill Math Grade 3 Answer Key PDF Chapter 1 Lesson 6 Problem-Solving Investigation: Use the Four-Step Plan** will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 3 Answer Key Chapter 1 Lesson 6 Problem-Solving Investigation: Use the Four-Step Plan

**Learn the Strategy**

Dina’s family went to a zoo on their vacation. They learned that a roadrunner is 1 foot tall. An African elephant is 12 feet tall. How much taller is an African elephant than a roadrunner?

1. Understand

What facts do you know?

The roadrunner is ____ foot tall.

The African elephant is ___ feet tall.

What do you need to find?

how much taller an African elephant is than a ____

2. Plan

____ the roadrunner’s height from the African elephant’s height.

3. Solve

So, the elephant is feet taller than the roadrunner.

4 Check

Does your answer make sense? Explain.

Answer:

The roadrunner is 1 foot tall.

The African elephant is 12 feet tall.

African elephant is 11 feet taller than roadrunner.

**Practice the Strategy**

Alex wants to buy a train ticket to his grandfather’s house. A one-way ticket costs $43. A round-trip ticket costs $79. Is it less expensive to buy 2 one-way tickets or one round-trip ticket?

1. Understand

What facts do you know?

__________

What do you need to find?

____________

2. Plan

____________

____________

3. Solve

4. Check

_________________

Answer:

Given that,

A one-way ticket costs $43.

A round-trip ticket costs $79.

Two one way tickets = $43 + $43 = $86.

Therefore less expensive to buy the one round- trip ticket.

**Apply the Strategy**

**Solve each problem by using the four-step plan.**

Question 1.

The table shows the number of play tickets four friends sold on Saturday.

Write the number of tickets sold by each friend in standard form. Then order the numbers from greatest to least.

Answer:

Given that,

The total number of tickets sold by Louise = 17

The standard form of 17 = 10 + 7.

The total number f tickets sold by Malcolm = 14

The standard form of 14 = 10 + 4.

The total number of tickets sold by Bobby = 15

The standard form of 15 = 10 + 5

The total number of tickets sold by Shelly = 21

The standard form of 21 is 20 + 1

Order the numbers from greatest to least is 21, 17, 15, 14.

Question 2.

Cameron and Mara walked 2 blocks. Then they turned a corner and walked 4 blocks. If they turned around now and returned home the way they came, how many blocks will they have walked altogether?

Answer:

Given that,

Cameron and Mara walked 2 blocks.

Then they turned a corner and walked 4 blocks.

If they turned around now and returned home the way they came.

Therefore they will 8 blocks to returned home the way they came.

Question 3.

**Mathematical PRACTICE 5 Use Math Tools** Follow the directions to find the correct height of the CN Tower in Toronto, Canada. Start with 781 feet. Add 100. Add 1,000. Subtract 7 tens, and add 4 ones.

Answer:

Given that,

The height of the CN Tower in Toronto, Canada. Start with 781 feet. Add 100. Add 1,000. Subtract 7 tens, and add 4 ones.

The height of the Tower = 781 + 100 + 1000 – 70 + 4 = 1885 – 70 = 1815

Therefore the height of the CN Tower in Toronto, Canada is 1815.

Question 4.

In 1,000 years from now, what year will it be? What year will it be 100 years from now? 10 years from now?

Answer:

This year is 2022.

This year from 1000 years = 2022 + 1000 = 3022.

This year from 100 years = 2022 + 100 = 2122.

This year from 10 years = 2022 + 10 = 2032.

**Review the Strategies**

Use any strategy to solve each problem.

- Use the four-step plan.
- Guess, check, and revise.
- Act it out.

Question 5.

The blue number cubes represent hundreds. The red number cubes represent tens. Write the standard form for each person’s set of number cubes.

Robin’s number cubes

_______

Percy’s number cubes

_______

Byron’s number cubes

_________

Order these numbers from greatest to least

Answer:

Given that,

Red cube represents the ten and blue cube represents hundred.

Robin’s number cubes are 8, 1, 5 = 800, 10, 500.

The order of Robin’s cube numbers from greatest to least is 800, 500, 10.

Percy’s number cubes are 4, 7, 5 = 40, 700, 500.

The order of Percy’s cube numbers from greatest to least is 700, 500, 40.

Byron’s number cubes are 5, 8, 6, 2 = 50, 800, 600, 20.

The order of Byron’s cube numbers from greatest to least is 800, 600, 50, 20.

Question 6.

**Mathematical PRACTICE 1 Plan Your Solution** Two students traveled during their summer vacation. Tina traveled 395 miles. Carl traveled 29 more miles than Tina. How many miles did Carl travel?

Answer:

Given that,

Two students traveled during their summer vacation.

Tina traveled 395 miles.

Carl traveled 29 more miles than Tina = 395 + 29 = 424

Therefore carl traveled 424 miles.

Question 7.

**Mathematical PRACTICE 6 Be Precise** A group of hikers traveled to the Adirondack Mountains. To the nearest ten, about how many feet did they hike if they climbed Big Slide Mountain and Algonquin Peak?

Is there any difference in the distance if you round to the nearest hundred instead? Use <, >, or = to explain.

Answer:

Given that,

Mt. Marcy hikers traveled to the Adirondack Mountains is 5,344 ft.

5,344 rounded to the nearest ten is 5,340.

5,344 rounded to the nearest hundred is 5,300

Algonquin Peak hikers traveled to the Adirondack Mountains is 5,114 ft.

5,114 rounded to the nearest ten is 5,110.

5,114 rounded to the nearest hundred is 5,100

Whiteface Mt. hikers traveled to the Adirondack Mountains 4,867 ft.

4,867 rounded to the nearest ten is 4,870.

4,867 rounded to the nearest hundred is 4,900.

Big Slide Mt. hikers traveled to the Adirondack Mountains 4,240 ft.

4,240 rounded to the nearest ten is 4,240.

4,240 rounded to the nearest hundred is 4,200.

Yes when the hikers are nearest to hundred there is difference.

Therefore, 5,100 > 4,870 < 4,900 > 4,200.

### McGraw Hill My Math Grade 3 Chapter 1 Lesson 6 My Homework Answer Key

**Problem Solving**

Question 1.

Victoria buys two pairs of sunglasses for $8 each. About how much did she pay for both pairs of glasses? Round to the nearest ten. Solve the problem using the four-step plan.

Answer:

Given that,

The total cost of sunglasses = $8.

The total cost of two sunglasses = $8 x 2 = $16.

16 rounded to the nearest ten is 20.

In 16 the ones place is greater than 5. So, replace the ones place by 0 and add 1 to the tens place.

**Solve each problem using the four-step plan.**

Question 2.

Ridgeway Elementary School collected eight thousand, five hundred thirty-one cans of food. Park Elementary School collected eight thousand, six hundred forty-two cans. Which school collected more cans of food? Write the greater number of cans in expanded form.

Answer:

Given that,

Ridgeway Elementary School collected eight thousand, five hundred thirty-one cans of food = 8531.

Park Elementary School collected eight thousand, six hundred forty-two cans = 8641.

Park Elementary School is greater than Ridgeway Elementary School

The expanded form of 8641 is 8000 + 600 + 40 + 1.

Question 3.

**Mathematical PRACTICE 1 Make a Plan** There are 398 students at Rebecca’s school and 462 students at Haley’s school. There are 10 more students at Ronnie’s school than there are at Rebecca’s school. Order the number of students at each school from least to greatest.

Answer:

Given that,

The total students at the Rebecca’s school = 398.

The total students at the Haley’s school = 462.

There are 10 more students at Ronnie’s school then Rebecca’s school = 398 + 10 = 408.

The order of the number in each school from least to greatest is 398; 408; 462.

Question 4.

**Mathematical PRACTICE 3 Justify Conclusions** The table shows the points each player scored in a video game. Who scored more points? Circle the player’s name.

In which place are the digits that helped you solve this problem?

Answer:

Given that,

The total points scored in the video game by Josh is 2,365.

The total points scored in the video game by Jake is 2,475.

Therefore Jake scored more points.

Question 5.

The distance from Los Angeles, California to New York, New York is 2,782 miles. What is the distance between the two cities rounded to the nearest hundred miles?

Answer:

Given that,

The distance from Los Angeles, California to New York is 2,782 miles.

2,782 rounded to the nearest hundred is 2,800.

In 2,782 the tens place is greater than 50. So, replace the ones and tens place by 0 and add 1 to the hundreds place.