Rounding

@lhmaths: Lesley Hall

To round 57 to the nearest ten …

50 60

... decide which two tens it lies between ..

57

... 57 is nearer to 60.

57 rounded to the nearest ten is 60.

Rounding

@lhmaths: Lesley Hall

To round 82 to the nearest ten …

80 90

... decide which two tens it lies between ..

82... 82 is nearer to 80.

82 rounded to the nearest ten is 80.

Rounding

@lhmaths: Lesley Hall

To round 25 to the nearest ten …

20 30

... decide which two tens it lies between ..

25... 25 is half way – it’s not nearer to 20 or 30

25 rounded to the nearest ten is 30.

If it’s half way we always round up.

Rounding

@lhmaths: Lesley Hall

To round 326 to the nearest ten …

320

330

... decide which two tens it lies between ..

326... 326 is nearer to 330.

326 rounded to the nearest ten is 330.

3 2 6 because the 6 is bigger than 5 (half way) we round up

Rounding

@lhmaths: Lesley Hall

To round 71 to the nearest ten …

711 is less than 5 (half way) so round down to 70

71 rounded to the nearest ten is 70.

To round 679 to the nearest ten …

679 9 is greater than 5 (half way) so round up to

680

679 rounded to the nearest ten is 680.

Rounding

@lhmaths: Lesley Hall

To round 326 to the nearest hundred …

300

400

... decide which two hundreds it lies between ..

326... 326 is nearer to 300.

326 rounded to the nearest hundred is 300.

3 2 6 because the 26 is less than 50 (half way) we round down

Rounding

@lhmaths: Lesley Hall

To round 151 to the nearest hundred …

151 51 is greater than 50 (half way) so round up to

200

151 rounded to the nearest hundred is 200.

To round 679 to the nearest hundred…

679

7 is greater than 5 (half way) so round up to 700

679 rounded to the nearest hundred is 700.

(or 79 is greater than 50(half way) so round up to 700)

Rounding

@lhmaths: Lesley Hall

To round 5.8 to the nearest unit (whole number) …

5 6

... decide which two units it lies between ..

5.8... 5.8 is nearer to 6.

5.8 rounded to the nearest unit is 6.

5.8 because the 8 is greater than 5 (half way) we round up

Rounding

@lhmaths: Lesley Hall

To round 2.7 to the nearest unit …

2.77 is greater than 5 (half way) so round up to 3

2.7 rounded to the nearest unit is 3.

To round 8.26 to the nearest hundred…

8.26 2 is less than 5 (half way) so round down to 8

8.26 rounded to the nearest unit is 8.

(the 6 doesn’t matter – only look at the next digit after the whole number)