We included **HMH Into Math Grade 3 Answer Key**** PDF** **Module 9 Lesson 6 Use Estimation with Sums and Differences**Â to make students experts in learning maths.

## HMH Into Math Grade 3 Module 9 Lesson 6 Answer Key Use Estimation with Sums and Differences

I Can use rounding and compatible numbers to estimate sums and differences and solve problems.

**Spark Your Learning**

Frida has $50 to buy a meal for her family of 4. What can she buy? About how much money will she have left over?

Answer:

She can buy every item on the menu

The sum of the total items given is $7 + $5 + $3 + $1 + $1 + $2 = $19

The left over amount is $50 – $19 = $31

Explanation:

Given Frida has $50.

She can buy a meal for her family with the given menu is $7 + $5 + $3 + $1 + $1 + $2 = $19.

The money left after buying a meal is = $50 – $19 = $31.

**Show your thinking.**

**Turn and Talk** If everyone orders the same meal, what is the most Frida can spend on each meal?

Answer:

The most Frida can spend on each meal is $7.

Explanation:

If everyone orders the same meal as a hamburger, the most Frida can spend on each meal is $7.

**Build Understanding**

1. Nick’s father buys him a book, a sweater, and a pair of shoes. About how much money does he spend? How can you use rounding to estimate?

**Round each price to the nearest ten.**

A. What operation will you use to solve?

Answer:

He spent $89 dollars.

Explanation:

Given,

Nick’s father bought him a book that is $16, a sweater for $28, and a pair of shoes is $45.

The money nick spent is $16 + $28 + $45 = $89

**Connect to Vocabulary**

An estimate is a number close to an exact amount. What about how many or how much.

Answer:

How much.

B. Estimate the amount Nickâ€™s father spends. Show your thinking.

Answer:

$90 dollars.

Explanation:

The amount Nickâ€™s father spends $90 dollars.

C. Will the actual amount that Nick’s father needs be greater than, less than, or equal to the estimate using the rounded numbers? How do you know?

Answer:

Greater than the actual amount.

Explanation:

Nick’s father spent a total of $89 dollars. So by rounding to the nearest number the estimated amount is $90 dollars.

**Turn and Talk** When is an estimate better than an exact answer?

Answer:

Estimation is actually useful when an exact answer isn’t needed. You can use estimation for problems related to trips, finances, and data analysis. Estimating is frequently done before adding or subtracting by rounding to figures that are easier to think about.

**Step It Out**

2. Shelly has saved $156. She wants to buy a microscope that costs $89. About how much money will she have left after buying the microscope? How can you use compatible numbers to estimate?

A. Think of numbers close to $156 and $89 that are easy to work with.

A compatible number for $156 is ___.

A compatible number for $89 is ___.

Answer:

The money left after buying the microscope is $156 – $89 = $ 67.

Explanation:

The money left after buying the microscope is $156 – $89 = $ 67.

A compatible number for $156 is $150 + $6

A compatible number for $89 is $80 + $9

**Connect to Vocabulary**

Compatible numbers are numbers that are easy to compute mentally and are close to real numbers. Think of numbers with a 0 or 5 in ones place.

B. What operation can you use?

C. About how much money will Shelly have left?

**Turn and Talk** Will the exact difference be greater than, less than, or equal to your estimate? How do you know?

**Check Understanding Math Board**

Question 1.

Key School has 337 students. Park School has 387 students. About how many students attend these schools? Use compatible numbers to estimate.

Answer:

724

Explanation:

Given,

Key school = 337 students

Park school = 387 students

The students to attend these schools are 300 + 30 + 7 + 300 + 80 + 7 = 724.

Question 2.

On Friday, 417 people attend the craft fair. On Saturday, 772 people attend the craft fair. About how many more people attend on Saturday than on Friday? Use rounding to estimate.

Answer:

772 – 417 = 355

Explanation:

Given,

People attend the craft fair on Friday = 417

People attend the craft fair on Saturday = 772

More people attended on Saturday than on Friday = 772 – 417 = 355.

**On Your Own**

Question 3.

**STEM** Birva conducts an experiment on heat transfer. Samples A and B are filled with water.

Birva added ice to Sample A and no ice to Sample B. After 5 minutes, Sample A is 46Â°F, and Sample B is 73Â°F. Estimate the difference in temperature. Show your thinking.

_______________

Answer:

27Â°F

Explanation:

Given, sample A is 46Â°F

Sample B is 73Â° F

The difference in temperature is 73Â°-46Â° = 27Â°

**Estimate the sum. Show your thinking.**

Question 4.

279 + 134 ___

Answer:

413.

Explanation:

The sum of the given numbers is 413.

Question 5.

688 + 106 ___

Answer:

794.

Explanation:

The sum of the given numbers is 794.

Question 6.

**Critique Reasoning** Mason and Nya estimate the difference for 524 – 365.

Mason uses compatible numbers. 525 – 350 = 175

Nya rounds to the nearest hundred. 500 – 400 = 1oo

Which estimate will be closer to the actual difference? Explain your thinking.

Answer:

The estimate difference for 524 – 365 = 159.

Therefore the estimate that will be closer to the actual difference is 500 – 400 = 100.

Explanation:

Nya rounds to the nearest hundred is the closer to the actual difference that is 500 – 400 =100.

**Estimate the difference. Show your thinking.**

Question 7.

702 – 435 ___

Answer:

267

Explanation:

The difference between the given numbers is 267.

Question 8.

612 – 449 ___

Answer:

163

Explanation:

The difference between the given numbers is 163.

**Iâ€™m in a Learning Mindset!**

What strategies do I have for remaining positive about learning?

_____________________________

Answer:

The strategies we use for remaining positive about learning are to Focus on the good things and practice positive self-talk.

Accepting challenging situations and obstacles is a part of life.