Transcript Chapter 2 Lesson 1

Five-Minute Check (over Lesson 1–8)
Main Idea and Vocabulary
Example 1: Round Whole Numbers
Example 2: Round Decimals
• I will round whole numbers and decimals.
• round
Round Whole Numbers
Omar traveled 8,157 miles last summer with his
family. Round 8,157 to the nearest thousand.
Step 1 Underline the digit in the
place to be rounded. In
this case, the 8 in the
thousands place is to be
rounded.
8,157
Step 2 Look at 1, the digit to the
right of the underlined digit.
8,157
Round Whole Numbers
Step 3 If this digit is 4 or less, do
not change the underlined
digit. Since 1 < 5, keep the
digit 8 the same.
8,157
Step 4 Replace all digits after the
underlined digit with zeros.
8,000
Answer: To the nearest thousand, 8,157 rounds
to 8,000.
Round Whole Numbers
Check for Reasonableness
On the number line, 8,157 is closer to 8,000 than to
9,000. So, the answer is reasonable.
Round 24,763 to the nearest thousand.
A. 20,000
B. 24,000
C. 25,000
D. 30,000
0%
0%
A
B
1.
2.
3.
4.
0%
C
A
B
C
D
0%
D
Round Decimals
Round 910.356 to the nearest tenth.
Step 1 Underline the digit in the
tenths place, 3.
910.356
Step 2 Look at 5, the digit to the
right of 3.
910.356
Round Decimals
Step 3 If this digit is 5 or greater,
add 1 to the underlined
digit. Since 5 = 5, add 1 to
the 3.
Step 4 Drop the digits after the
underlined digit.
Answer: So, 910.356 rounds to 910.4.
910.356
910.4
Round Decimals
Check for Reasonableness
On the number line, 910.356 is closer to 910.4 than
to 910.3. So, the answer is reasonable.
Round 47.324 to the nearest tenth.
A. 47
B. 47.3
C. 47.4
D. 48
0%
0%
A
B
1.
2.
3.
4.
0%
C
A
B
C
D
0%
D
End of the Lesson
Five-Minute Check (over Lesson 1–8)
Image Bank
Math Tool Chest
Add and Subtract Decimals
(over Lesson 1–8)
Use the guess and check strategy to solve.
Willie has 11 coins in his pocket. More than half are
quarters, only one coin is a dime, and he has the same
number of nickels as pennies. He has less than $2.00.
How much money does Willie have?
$1.48 (5 quarters, 1 dime,
2 nickels, 3 pennies)
D.
$2.16 (8 quarters, 1 dime,
1 nickel, 1 penny)
$1.78 (6 quarters, 1 dime,
3 nickels, 3 pennies)
0%
A
C.
1.
2.
3.
0%4.
A
B
C
0%D
0%
D
B.
C
$1.72 (6 quarters, 1 dime,
2 nickels, and 2 pennies)
B
A.