|
You can round
numbers to tell about
how much or about how
many.
Rounding is
one way to estimate.
To
round numbers:
-
Find the place you
are rounding to.
-
Look at the digit
to its right.
If
the digit to the right of the place one is rounding to is
less
than 5, round down 
;
if it is 5 or greater, round up  .
 
|
The
box on the right shows two numbers and the number halfway
between them. Write the number to be rounded above or below
the dividing halfway line in the box on the left.
Round 36 to the nearest ten. |
| |
30 |
|
------------------------------ |
35 |
|
36 |
40 |
|
36
is greater than 35, so 36 is
closer to 40. 36 rounded to the
nearest 10 is 40. |
|
|
The
box on the right shows two numbers and the number halfway
between them. Write the number to be rounded above or below
the dividing halfway line in the box on the left.
Round 142 to the nearest hundred. |
|
142 |
100 |
|
------------------------------ |
150 |
|
|
200 |
|
142
is less than 150, so 142 is closer to 100.
142 rounded to
the nearest 100 is 100. |
|
|
The
box on the right shows two numbers and the number halfway
between them. Write the number to be rounded above or below
the dividing halfway line in the box on the left.
Round 1631 to the nearest thousand. |
| |
1,000 |
|
------------------------------ |
1,500 |
|
1,631 |
2,000 |
|
1,631
is greater than 1,500, so 1,631
is closer to 2,000. 1,631 rounded to the
nearest 1,000 is 2,000. |
|
|
Using a number
line |
|
 |
|
0 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
|
|
Round
75 to the nearest
ten.
75 is halfway between 70 and 80, so round to
80. |
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Let's
Practice!
click
here
|
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When a number is
halfway between two numbers, round
to the greater number. |
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