Notes Over 3

1
Notes Over 3 1
Round each number to the given place value.
1. Round 8.7398 to the nearest
7
a. tenth
Since the 3 in the hundredths place is lower than
5, the 7 in the tenths place stays a 7.
Drop everything past the 7.
8.7
2
Notes Over 3 1
Round each number to the given place value.
1. Round 8.7398 to the nearest
8
a. tenth
b. integer
Since the 3 in the hundredths place is lower than
5, the 7 in the tenths place stays a 7.
Since the 7 in the tenths place is higher than 5,
the 8 in the ones place becomes a 9.
Drop everything past the 7.
Drop everything past the decimal.
8.7
9
3
Notes Over 3 1
Round each number to the given place value.
2. Round 7,098.56 to the nearest
0
a. hundred
Since the 9 in the tens place is higher than 5,
the 0 in the hundreds place becomes a 1.
Everything behind the 1 becomes a 0 up to the
decimal.
7,100
4
Notes Over 3 1
Round each number to the given place value.
2. Round 7,098.56 to the nearest
5
a. hundred
b. tenth
Since the 9 in the tens place is higher than 5,
the 0 in the hundreds place becomes a 1.
Since the 6 in the hundredths place is higher
than 5, the 5 in the tenths place becomes a 6.
Everything behind the 1 becomes a 0 up to the
decimal.
Drop everything past the 5.
7,100
7,098.6
5
Notes Over 3 1
3. Estimate by Rounding.
a. 4.89
5
3.87
4


9
450
b. 453.56
230.07
230
-
-
220
6
Notes Over 3 1
4. Estimate by Front-End Estimation.
a. 14.39
1
4
79.102
7
9



80
93
13
.3
b. 2.298
2
7.750
.8
7



10.1
1.1
9
7
Notes Over 3 1
5. Estimate by Clustering.
a. 4.50 5.20 5.55
Since all of them are close to 5, you can
multiply
15
X
5
3
b. 26.7 26.2 24.52 25.25 23.9
Since all of them are close to 25, you can
multiply
125
X
25
5
8
Notes Over 3 2
1. Estimate by Rounding.
.
4.7
6.43
.
6
30
5
9
Notes Over 3 2
2. Joshua bought 3 yards of fabric to make a
dress. The fabric cost 5.65/yd. The clerk said
his total was 14.95 before tax. Did the clerk
make a mistake? Explain.
.
3
5.65
.
YES
18
6
3
.
It should have cost between 15 and 18.
15
5
3
10
Notes Over 3 2
Estimate by using Compatible Numbers.
1.79
3. 38.9
38
2
19
4.25
4. 82.52
84
4
21
11
Notes Over 3 2
6
30
5
NO
It should have been closer to 5.
12
Page 125, 3 1 1-13, 14-46 even Page 129, 3
2 1-8, 10-30 even