All the solutions provided in **McGraw Hill My Math Grade 3 Answer Key PDF Chapter 7 Lesson 6 Problem-Solving Investigation: Extra or Missing Information **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 3 Answer Key Chapter 7 Lesson 6 Problem-Solving Investigation: Extra or Missing Information

**Learn the Strategy**

The school’s hayride starts at 6 P.M. There are 4 wagons that can hold 9 children each. Half of the children going are girls. What is the total number of children that can ride on the wagons?

1. Understand

What facts do you know?

The hayride starts at ____________ P.M.

There are ____________ wagons that hold ______________ children each.

Half of the children are girls.

What do you need to find?

the number of _____________ that can ride on the 4 wagons

2. Plan

Decide what facts are important,

the number of _____________ the number of ____________ each wagon holds

3. Solve

4. Check

Does your answer make sense? Explain.

Answer:

The hayride starts at 6 P.M.

There are 4 wagons that hold 9 children each.

The number of children’s are 9 x 4 = 36.

Half of the children are girls.

so, 36/2 = 18.

The number of girls in the wagons are 18.

**Practice the Strategy**

An animal shelter has 23 cats and 14 dogs. How much would it cost to adopt 1 cat and 1 dog? Tell what facts are extra or missing.

1. Understand

What facts do you know?

What do you need to find?

2. Plan

3. Solve

4. Check

Does your answer make sense? Explain.

Answer:

Given that,

An animal shelter has 23 cats and 14 dogs.

To find the cost to adopt 1 cat and 1 dog in the question they missed the information regarding the cost of each adopt.

It is not possible to solve without the information of cost of each adopt.

**Apply the Strategy**

**Determine if there is extra or missing information to solve each problem. Then solve if possible.**

Question 1.

**Mathematical PRACTICE** Draw a Conclusion Mrs. Friedman had 2 boxes of chalk. She bought 4 more boxes with 10 pieces each. She paid $2 per box. How much did she spend on the 4 boxes of chalk?

Answer:

Given that,

Mrs. Friedman had 2 boxes of chalk.

She bought 4 more boxes with 10 pieces each.

The total number of boxes are 2 + 4 = 6.

She paid $2 per box.

The total cost of 6 boxes are 6 x $2 = $12.

The cost of 4 boxes of chalk is $2 x 4 = $8.

Therefore she spend on the 4 boxes of chalk is $8.

Question 2.

Bert bought 4 of each of the items below. How much change did he get back?

Answer:

Given that,

Bert bought 4 of each of the items below.

In the above they did missed the information about that the Bert spend on the items.

So, it is not possible to solve.

Question 3.

**Mathematical PRACTICE** Use Math Tools Alejandra is 58 inches tall. Her sister is in the first grade and is 10 inches shorter than Alejandra. What known fact when doubled, is equal to the height of Alejandra’s sister?

Answer:

Alejandra is 58 inches tall.

Her sister is 10 inches shorter than Alejandra.

The extra information is Her sister is in the first grade.

If double the sisters height it is 10 + 10 = 20 inches.

Therefore the fact is if you double the sisters height also the Alejandra is taller than sister.

**Review the Strategies**

Use any strategy to solve each problem.

- Determine extra or missing information.
- Make a table.
- Look for a pattern.
- Use models.

Question 4.

Ten of Eduardo’s baseball cards are All Star cards. His friend has four times as many All Star cards. How many All Star baseball cards does his friend have?

Answer:

Given that,

The All star baseball cards near the Eduardo’s is 10.

His friend has four times as many All Star cards.

So, His friend has 10 x 4 = 40.

Therefore the All Star baseball cards with his friend is 40.

Question 5.

The third grade class had four chicks hatch every day for 5 days. Nine of the chicks were yellow, and the rest were brown. How many chicks hatched in all?

Answer:

Given that,

The third grade class had four chicks hatch every day for 5 days.

The number of chicks for 5 days is 5 x 4 = 20.

The extra information is nine of the chicks were yellow, and the rest were brown.

Therefore the number of chicks hatched in all is 20.

Question 6.

Four friends bought a total of 24 computer games. Each friend bought the same number of games. How many games did each friend buy?

Answer:

Given that,

Four friends bought a total of 24 computer games.

Each friend bought the same number of games.

The number of computer games for each person is 24/4 = 6.

Therefore the number of computer games for each person is 6.

Question 7.

**Mathematical PRACTICE** Make Sense of Problems There are 4 sheets of stickers. Each sheet has 7 stickers. Kyla gives 1 sheet of stickers to her friend. How many stickers does Kyla have left?

Answer:

Given that,

There are 4 sheets of stickers.

Each sheet has 7 stickers.

Kyla gives 1 sheet of stickers to her friend.

Known the number of stickers are 4 – 1 = 3.

The number of stickers with Kyla is 7 x 3 = 21.

Therefore the number of stickers does Kyla have left is 21.

Question 8.

How many dots will there be altogether if there are 2 dominoes like the one below?

Answer:

Each die has 6 sides.

In two dies 1 side is 1. Then 1 + 1 = 2.

2nd side is 2 then 2 + 2 = 4.

3rd side is 3 then 3 + 3 = 6.

4th side is 4 then 4 + 4 = 8.

5th side is 5 then 5 + 5 = 10.

6th side is 6 then 6 + 6 = 12.

The number of dots are 2 + 4 + 6 + 8 + 10 + 12 = 42.

Therefore the number of dots are 42.

### McGraw Hill My Math Grade 3 Chapter 7 Lesson 6 My Homework Answer Key

**Problem Solving**

**Determine if there is extra or missing information to solve each problem. Then solve if possible.**

Question 1.

Brandy ate 9 corn chips for a snack. She ate twice as many raisins. She also drank a juice box. How many raisins did Brandy eat?

Answer:

Given that,

Brandy ate 9 corn chips for a snack.

She ate twice as many raisins. It means 9 x 2 = 18.

She ate 18 raisins.

The extra information is She also drank a juice box.

Therefore the number of raisins did Brandy ate is 18.

Question 2.

Miguel bought a movie ticket that cost $5. He also bought popcorn and a bottle of water. How much did Miguel spend altogether?

Answer:

Given that,

Miguel bought a movie ticket that cost $5.

He also bought popcorn and a bottle of water.

In the question they missed the information about the cost of popcorn and water bottle.

It is not possible to solve the Miguel spend altogether.

Question 3.

Annie has basketball practice from 2:30 P.M. to 4:00 P.M. She makes 10 free throws every practice. How many free throws does she make in 4 practices?

Answer:

Given that,

Annie has basketball practice from 2:30 P.M. to 4:00 P.M.

She makes 10 free throws every practice.

The number of practices are 4.

So, 4 x 10 = 40.

Therefore the number of free throws she make in 4 practices is 40.

Question 4.

Naya has 12 flowers. She gives away 6 to Jane and 3 to Heather. Hannah does not have any flowers. How many flowers does Naya have left?

Answer:

Given that,

Naya has 12 flowers.

She give 6 to Jane and 3 to Heather.

The extra information is Hannah does not have any flowers.

The number of flowers given to Jane and Heather is 6 + 3 = 9.

The number of flowers left near Naya is 12 – 9 = 3.

Therefore the number of flowers left near Naya is 3.

Question 5.

**Mathematical PRACTICE** Draw a Conclusion Juan bought two new tires for his bike. He also had the bike tuned up. The total bill was $65. How much did Juan spend on the 2 tires?

Answer:

Juan bought two new tires for his bike.

He also had the bike tuned up.

In the question they didn’t give the information about the cost of bike tuned up.

The total bill was $65.

It is not possible to solve the Juan spend on the 2 tires.