rounding

Rounding

Intro 63.91 to Nearest Whole Number

Nearest Whole Number

Nearest Ten

Nearest Hundred

To 1 Decimal Place

Rounding By Interactive Example

Rounding Seven Questions

Rounding

When you use a tape measure to work out the length of a table often you give the answer to the nearest cm. This is known as ROUNDING You are often asked to ROUND an answer that you get on a calculator. What is 63.91 to the nearest Whole Number

63.0 63.1 63.2 63.3 63.4 63.5 63.6 63.7 63.8 63.9 64.0

0 1 2 3 4 5 6 7 8 9The “scale” shows numbers between 63 and

64.

Where is 63.9163.9

063.9

163.92 63.93 63.9

463.9

563.96 63.97 63.98 63.9

964.00

Can you see that 63.91 is closer to 64.0

Rounding 63.91 to a Whole Number

What is 63.91 to the nearest Whole Number

63.0 63.1 63.2 63.3 63.4 63.5 63.6 63.7 63.8 63.9 64.0

0 1 2 3 4 5 6 7 8 9

A What two WHOLE numbers is 63.91 between 63 and 64

B What is the figure after 63 9

9 is called the ROUND FIGURE

If Round Figure is 01234 ROUND to 63

The scale can be split into TEN sections using the ROUND FIGURE

If Round Figure is 56789 ROUND to 64 Answer 64

Round 15.5 to nearest Whole Number

Step 1 What is LOW

Step 2 Next Figure is Round Figure

15

5

Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW

ROUND to 16

1615.5 to nearest whole number is

1 5 . 5

1 5 . 5

Whole number

Hide the decimal part to get LOW

Round Figure

No!

Sep 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High

After 15 is 16

Round 28.3 to Nearest whole number

Step 1 What is LOW


28

3


ROUND to 28

2828.3 to nearest whole number is

2 8 . 3

2 8 . 3

Whole number

Hide the decimal part to get LOW

Round Figure

Yes!

Round 89 to nearest Ten

Step 1 What is LOW

Step 2 Above 1st 0 is Round Figure

80

9


ROUND to 90

9089 to nearest Ten 8 9

8 9

10, 20, 30 ….. Must end in a 0 ….. Figure before Units Plus 0

Round Figure

No!

Step 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High

80 + 10 is 90

0

Round 324 to nearest Ten

Step 1 What is LOW

Step 2 1st Figure to be replaced is Round Figure

320

4


ROUND to 320

320324 to nearest Ten 2 4

2 4

10, 20, 30 ….. Must end in a 0 ….. Figure before Units Plus 0

Round Figure

Yes!

0

3

3

Round 1995 to nearest Hundred

Step 1 What is LOW

Step 2 Above 1st 0 is Round Figure

1900

9


ROUND to 2000

2001995 to nearest Hundred 1 9

9 5

100, 200, 300 ….. Must end in a 00 ….. Figure before Tens Plus 00

Round Figure

No!


1900 + 100 is 2000

0

9 5

91

0

Round 9.95 to 1 Decimal Place

Step 1 What is LOW


9.9

5


No!

10.09.95 to 1dp is 9 . 9 5

9 . 9 5

1dp

Cover number then move to the right until there is one figure after the point

Round Figure


After 9.9 is 10.0

ROUND to 10.0

Round 8.832 to 1 Decimal Place

Step 1 What is LOW


7.8

3


ROUND to 7.8

7.87.832 to 1dp is 7 . 8 3 2

7 . 8 3 2

1dp

Cover number then move to the right until there is one figure after the point

Round Figure

Rounding … By Example

0 1 2 3 4

5 6 7 8 9

C

.

÷x

0+ On

²

-

Ans

=

√(-)

600 610 620 630 640 650 660 670 680 690 700

Round 672 To Nearest Hundred

6 2

0 1 2 3 4 5 6 7 8 9

Low High

Click Round Fig

Start

Is between and

Show Scale

7

Nearest Hundred

ROUND

990

762

194

927

885

981

436

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Next

Nearest Hundred

To Nearest Hundred

Show Ans 0 1 2 3 4

5 6 7 8 9

C

.

÷x

0+ On

²

-

Ans

=

√(-)

C

0

1 2 3

4 5 6

7 8 9

C

.

÷

x

0

+

On

²

-

Ans

=

√

(-)

0 1 2 3 4

5 6 7 8 9

C

.

÷x

0+ On

²

-

Ans

=

√(-)Test

rounding

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