We included **HMH Into Math Grade 4 Answer Key**** PDF** **Module 2 Lesson 2 Subtract Whole Numbers and Assess Reasonableness** to make students experts in learning maths.

## HMH Into Math Grade 4 Module 2 Lesson 2 Answer Key Subtract Whole Numbers and Assess Reasonableness

I Can subtract whole numbers greater than 1,000 using place value and a grid with regrouping.

**Spark Your Learning**

Biologists classify living things on Earth by kingdoms. The approximate number of species in two different kingdoms are shown How many more fungi species are there than plant species?

Write the difference using only numbers.

**Turn and Talk** How did you know that you needed to regroup some of the place values?

Explanation:

**Build Understanding**

Question 1.

A natural history museum has 102,248 spider and scorpion specimens and 10,425 bird specimens. How many more spider and scorpion specimens are there than bird specimens?

**Use the grid to help you solve the problem.**

A. How can you use subtraction to solve this problem?

_____________________________

_____________________________

_____________________________

102,248 spider and scorpion specimens

and 10,425 bird specimens.

102,248 – 10,248= 92,000

B. Which place value should you start with when subtracting? _____________

Explanation:

When we do subtract we subtract from ones place

C. Subtract to find the answer.

Explanation:

D. Which place values did you regroup?

_________________________

Explanation:

we regrouped the thousands place

E. Use rounding to estimate the answer. Does your estimate show your answer is reasonable? Explain.

102,248 is rounded to 100,000

10,248 is rounded to 10,000

100,000 – 10000 = 90,000

My estimation is reasonable

as my exact answer is slightly vary to the exact answer.

**Turn and Talk** Does the estimated difference being close to your answer mean your answer is correct? Explain.

yes.

If the estimated difference is being close to our answer mean our answer is correct.

**Step It Out**

2. Of the 41,415 plant and animal species on a conservation group’s endangered species list, 16,306 are listed as near extinction. How many of the species on the list are not considered near extinction?

Explanation:

41,415 plant and animal species

16,306 are listed as near extinction

41,415 – 16,306 = 25,209

A. Estimate. Round to the nearest ten thousand. Then subtract. ____

41,415 – is rounded to 41,000

16,306 is round to 16000

41,000 – 16,000 = 25,000

B. Use the grid to record the problem.

C. Subtract the ones.

Explanation:

Continue to subtract by place value. What place values need to be regrouped?

Explanation:

We regrouped in ones place

There are ___ species considered endangered but not yet near extinction.

Explanation:

There are 25,000 species considered endangered but not yet near extinction.

D. Does your estimate show your answer is reasonable? Explain.

Explanation:

Yes, my answer is reasonable

as the estimation and exact answers are slightly varied.

**Check Understanding Math Board**

Question 1.

A scientific database lists 7,858 species of amphibians, and another database lists 5,513 species of mammals. How many more amphibian species than mammal species are listed?

There are ______ more amphibian species listed than mammal species.

Answer:

Explanation:

7,858 species of amphibians,

and another database lists 5,513 species of mammals.

7858 – 5513 = 2345

There are 2345 more amphibian species listed than mammal species.

**Estimate. Then find the difference.**

Question 2.

Estimate: ____

Answer:

Explanation:

518,112 is rounded to 500,000

295763 is rounded to 300,000

500,000 – 300,000 = 200,000

Question 3.

Estimate: ____

Answer:

Explanation:

560723 is rounded to 560,000

48911 is rounded to 50,000

560,000 – 50,000 = 510000

Question 4.

Estimate: ___

Answer:

Explanation:

5760 is rounded to 6000

2695 is rounded to 3000

6000 – 3000 = 3000

**On Your Own**

Question 5.

**STEM** At present, the highest peak of the Appalachian Mountains is 6,684 feet. Millions of years ago, before weathering and erosion had occurred, the highest peak was about 30,000 feet. What is the difference between the highest peak millions of years ago and the highest peak today? Explain how you know your answer is reasonable.

Answer:

the highest peak was about 30,000 feet.

the highest peak of the Appalachian Mountains is 6,684 feet

30,000 – 6,684 = 23,316

23,316 is the difference between the highest peak millions of years ago and the highest peak today

Question 6.

Use Structure Some biologists predict that there are about 27,500 species in the kingdom chromista and 36,400 species in the kingdom protozoa. How many more species of protozoa are predicted to exist than species of chromista? _____________

Answer:

27,500 species in the kingdom chromist

36,400 species in the kingdom protozoa

36,400 – 27,500 = 8,900

8,900 more species of protozoa are predicted to exist than species of chromist.

**Estimate. Then find the difference.**

Question 7.

Estimate: ______

Answer:

Explanation:

460,112 is rounded to 460,000

201,998 is rounded to 200,000

460,000 – 200,000 = 260,000

Question 8.

Estimate: ____

Answer:

Explanation:

8000 is rounded to 8000

2543 is rounded to 3000

8000 – 3000 = 5000

Question 9.

Estimate: ______

Answer:

Explanation:

88,741 is rounded to 88,000

16,304 is rounded to 16,000

88,000 – 16,000 = 72,000

Question 10.

**Open Ended** Write and solve a problem that requires finding the difference between 68,324 and 12,608.

_____________________________

_____________________________

Answer:

68,324

and 12,608.

**I’m in a Learning Mindset!**

How did subtracting greater numbers challenge me?

_____________________________

Explanation:

The regrouping makes the subtracting easier.