Go through the Math in Focus Grade 3 Workbook Answer Key Chapter 2 Practice 4 Rounding Numbers to Estimate to finish your assignments.

## Math in Focus Grade 3 Chapter 2 Practice 4 Answer Key Rounding Numbers to Estimate

**Mark (✗) each number on the number line.**

Question 1.

Answer:

Question 2.

Answer:

Question 3.

Answer:

**Fill in the blanks.**

Example

570 is nearer to __600__ than to __500__

570 is __600__ when rounded to the nearest hundred.

Question 4.

845 is nearer to ___ than to ____

845 is ___ when rounded to the nearest hundred.

Answer:

845 is nearer to 8__00__ than to 9__00__

845 is 8__00__ when rounded to the nearest hundred.

Question 5.

950 is nearer to ___ than to ____

950 is ___ when rounded to the nearest hundred.

Answer:

950 is nearer to 900 or 1000

950 is 900 or 1000 when rounded to the nearest hundred.

**Decide whether to find an estimate or an exact answer. Solve.**

Example

An organization has about 600 members,

The greatest possible number of members this con be is __649__.

The least possible number of members could be __550__

Question 6.

Tanya had $900. After buying two of these items, she has $210 left.

a. How much do the two items cost?

Answer:

Given,

Tanya had $900.

She left with $210.

a)

$900 – $210 = $ 690

She left with $690.

b. Which two items does she buy?

Answer:

b)

She bought TV and Washing Machine worth $450 and $240.

**Find the sum or difference. Use rounding to check that each answer is reasonable.**

Example

763 + 136 = __899__

763 is about __800__.

136 is about __100__.

__800__ + __100__ = __900__

So, 763 + 136 is about __900__

__899__ is close to __900__, so the answer is reasonable.

Question 7.

238 + 598 = ___

238 is about ____

598 is about ____

___ + ___ = ___

So, 238 + 598 is about ____

___ is close to ___, so the answer is reasonable.

Answer:

238 + 598 = 836

238 is about 200

598 is about 600

200 + 600 = 800

So, 238 + 598 is about 800

836 is close to 800, so the answer is reasonable.

Question 8.

846 – 694 = ____

846 is about ___

694 is about ____

___ – ___ = ____

So, 846 – 694 is about ___

___ is close to ___, so the answer is reasonable.

Answer:

846 – 694 = 152

846 is about 800

694 is about 700

800 – 700 = 100

So, 846 – 694 is about 100

152 is not close to 100, so the answer is not reasonable.

Question 9.

872 – 259 = ___

872 is about ___

259 is about ___

___ – ___ = ____

So, 872 – 259 is about ___

___ is close to ___, so the answer is reasonable.

Answer:

872 – 259 = 613

872 is about 900

259 is about 300

900 – 300 = 600

So, 872 – 259 is about 600

613 is close to 600, so the answer is reasonable.

Question 10.

Mrs. Ramsey wants to buy these four items.

a. Find the total cost of the items. Then, use rounding to check that the total cost is reasonable.

Answer: Total cost of the items = $96 + $215 + $247 +$385 + $943

b. Mrs. Ramsey has $980. Does she have enough money to buy all the items?

Answer: Yes, she has enough money to buy all the items. $990 – $943 = $37.