Transcript How to round a number with two decimal places to the nearest tenth

How to Round a Number to the
Nearest Tenth (1 Decimal Place)
Place Value Review
ths
Notice the decmal point. All places to the right
of the decimal end with “ths”
For you notebook (copy this):
• Rounding Decimals: to round a decimal to a given
place value, look at the digit in the place to the
right.
• If the digit is 4 or less, round down.
• If the digit is 5 or greater, round up.
First look at the value of the digit in
the hundredths column
4.675
Has 7 hundredths
First look at the value of the digit in
the hundredths column
4.675
Has 7 hundredths
5.85
Has 5 hundredths
First look at the value of the digit in
the hundredths column
4.675
Has 7 hundredths
5.85
Has 5 hundredths
3.7298
Has 2 hundredths
First look at the value of the digit in
the hundredths column
4.675
Has 7 hundredths
5.85
Has 5 hundredths
3.7298
Has 2 hundredths
4.23045
Has 3 hundredths
You round down to the nearest tenth if
the hundredths digit is 0,1,2,3 or 4.
3.726 is rounded down to 3.7
You round down to the nearest tenth if
the hundredths digit is 0,1,2,3 or 4.
3.726 is rounded down to 3.7
4.23 is rounded down to 4.2
You round down to the nearest tenth if
the hundredths digit is 0,1,2,3 or 4.
3.726 is rounded down to 3.7
4.23 is rounded down to 4.2
17.5178 is rounded down to 17.5
You round down to the nearest tenth if
the hundredths digit is 0,1,2,3 or 4.
3.726 is rounded down to 3.7
4.23 is rounded down to 4.2
17.5178 is rounded down to 17.5
120.60124 is rounded down to 120.6
You round down to the nearest tenth if
the hundredths digit is 0,1,2,3 or 4.
3.726 is rounded down to 3.7
4.23 is rounded down to 4.2
17.5178 is rounded down to 17.5
120.60124 is rounded down to 120.6
45.44008 is rounded down to 45.4
You round up to the nearest tenth if
the hundredths digit is 5,6,7,8 or 9.
4.67 is rounded up to 4.7
You round up to the nearest tenth if
the hundredths digit is 5,6,7,8 or 9.
4.67 is rounded up to 4.7
5.8577 is rounded up to 5.9
You round up to the nearest tenth if
the hundredths digit is 5,6,7,8 or 9.
4.67 is rounded up to 4.7
5.8577 is rounded up to 5.9
17.7802 is rounded up to 17.8
You round up to the nearest tenth if
the hundredths digit is 5,6,7,8 or 9.
4.67 is rounded up to 4.7
5.8577 is rounded up to 5.9
17.7802 is rounded up to 17.8
125.29 is rounded up to 125.3
You round up to the nearest tenth if
the hundredths digit is 5,6,7,8 or 9.
4.67 is rounded up to 4.7
5.8577 is rounded up to 5.9
17.7802 is rounded up to 17.8
125.29 is rounded up to 125.3
46.36445 is rounded up to 46.4
Watch out for numbers which have 9
in the tenths column.
e.g. 2.97
If you are rounding up, you will make 10
tenths. This makes 1 unit, so you have to
round to the next whole number (in this case
to 3).
Watch out for numbers which have 9
in the tenths column.
e.g. 2.97
If you are rounding up, you will make 10
tenths. This makes 1 unit, so you have to
round to the next whole number (in this case
to 3).
For the same reason, 23.964 becomes 24
Watch out for numbers which have 9
in the tenths column.
e.g. 2.97
If you are rounding up, you will make 10
tenths. This makes 1 unit, so you have to
round to the next whole number (in this case
to 3).
For the same reason, 23.964 becomes 24
12.9505 becomes 13
Watch out for numbers which have 9
in the tenths column.
e.g. 2.97
If you are rounding up, you will make 10
tenths. This makes 1 unit, so you have to
round to the next whole number (in this case
to 3).
For the same reason, 23.964 becomes 24
12.9505 becomes 13
And 6.98 becomes 7
EXAMPLE 1
Using a Number Line to Round
Use a number line to round 3.87 to the nearest tenth.
EXAMPLE 1
Using a Number Line to Round
Use a number line to round 3.87 to the nearest tenth.
EXAMPLE 1
Using a Number Line to Round
Use a number line to round 3.87 to the nearest tenth.
ANSWER
EXAMPLE 1
Using a Number Line to Round
Use a number line to round 3.87 to the nearest tenth.
ANSWER
The decimal 3.87 rounds up to 3.9.
GUIDED PRACTICE
for Example 1
Use a number line to round the decimal as specified.
GUIDED PRACTICE
for Example 1
Use a number line to round the decimal as specified.
1. 1.3
(nearest one)
for Example 1
GUIDED PRACTICE
Use a number line to round the decimal as specified.
1. 1.3
1
2.0
(nearest one)
1. 1
1. 2
1. 3
1. 4
1. 5
1. 6
1. 7
1. 8
1.9
for Example 1
GUIDED PRACTICE
Use a number line to round the decimal as specified.
1. 1.3
1
2.0
(nearest one)
1. 1
1. 2
1. 3
1. 4
1. 5
The decimal 1.3 is closer to 1 than to 3
1. 6
1. 7
1. 8
1.9
for Example 1
GUIDED PRACTICE
Use a number line to round the decimal as specified.
1. 1.3
1
2.0
(nearest one)
1. 1
1. 2
1. 3
1. 4
1. 5
The decimal 1.3 is closer to 1 than to 3
ANSWER
The decimal 1.3 rounds down to 1.
1. 6
1. 7
1. 8
1.9
That’s it for now......