## Envision Math 5th Grade Textbook Answer Key Topic 2.2 Rounding Whole Numbers and Decimals

How can you round whole numbers and decimals?

Rounding replaces one number with another number that tells about how many or how much. Round 634 to the nearest hundred.

**Another Example**

How do you round 2.36 to the nearest tenth? Is 2.36 closer to 2.3 or 2.4?

Think Is 2.36 closer to 2.3 or 2.4?

Step 1

Find the rounding place. Look at the digit to the right of the rounding place.

2.__3__6

Step 2

If the digit is 5 or greater, add 1 to the rounding digit. If the digit is less than 5, leave the rounding digit alone.

Since 6 > 5,

add 1 to the 3.

Step 3

Drop the digits to the right of the rounding digit.

2.36 rounds to 2.4

**Guided Practice***

Do you know HOW?

In 1 through 6, round each number to the place of the underlined digit.

Question 1.

__1__6

Answer:

Question 2.

5__6__.1

Answer:

Question 3.

1.__3__2

Answer:

Question 4.

4__2__7,841

Answer:

Question 5.

__1__,652

Answer:

Question 6.

__5__82,062

Answer:

Do you UNDERSTAND?

Question 7.

To round 7,458 to the nearest hundred, which digit do you look at? What is 7,458 rounded to the nearest hundred?

Answer:

Question 8.

A runner is running on a track with markers every 10 meters. If the runner has run 368 meters, is she closer to the 360-meter marker or

the 370-meter marker?

Answer:

Step 1

Find the digit in the rounding place. Underline this digit.

__6__34

Step 2

Look at the digit to the right of the rounding place. If this digit is 5 or greater, add 1 to the rounding digit. If the digit is less than 5, leave the rounding digit alone.

Leave 6 the same

Step 3

Change all the digits to the right of the rounding digit to zeros.

634 rounds to 600.

**Independent Practice**

In 9 through 16, round each whole number to the place of the underlined digit.

Question 9.

__6__77

Answer:

Question 10.

4,5__2__6

Answer:

Question 11.

12,__0__64

Answer:

Question 12.

5__7__3

Answer:

Question 13.

3__4__,739

Answer:

Question 14.

__5__9,304

Answer:

Question 15.

93__0__,998

Answer:

Question 16.

74__8__,397

Answer:

In 17 through 24, round each number to the place of the underlined digit.

Question 17.

7__5__.8

Answer:

Question 18.

0.7__5__8

Answer:

Question 19.

64__3__.82

Answer:

Question 20.

0.__4__72

Answer:

Question 21.

84.__7__32

Answer:

Question 22.

738.__2__9

Answer:

Question 23.

5.0__2__8

Answer:

Question 24.

23.00__9__

Answer:

**Problem Solving**

Question 25.

The world’s largest aloha shirt is 4.26 meters around the chest. Round 4.26 to the nearest ones place and nearest tenths place.

Answer:

Question 26.

In the first 3 quarters of a basketball game, a team scored 17, 25, and 13 points. Their final score was 75. How many points did the team score in the fourth quarter?

Answer:

Question 27.

An African Watusi steer’s horn measures 95.25 cm around. What is 95.25 when rounded to the nearest tenth? Nearest whole number? Nearest ten?

Answer:

Question 28.

In a recent year, the population of Illinois was 12,653,544. What is that population when rounded to the nearest million?

A. 10,000,000

B. 12,000,000

C. 12,600,000

D. 13,000,000

Answer:

Question 29.

The world land speed record set on October 15, 1997, was 763.03 miles per hour. What is this speed rounded to the nearest ones place?

Answer: