Rounding Understand how to round numbers to the nearest 10, whole number or decimal place.

Starter – order decimals Which value is the bigger? km km cm 7.30 cm

Starter – order decimals Put these in order, smallest first

What is the value… 3 4 5

Round the following number to 1dp Firstly, highlight the number to the first number after the decimal point So we have 6.3 But is this the answer? Now look at the number immediately after where we stopped highlighting If this number is a 0, 1, 2, 3 or 4 we don’t have to do anything else and we have our answer.

Round the following number to 1dp = 6.3 (1dp)

What if the red number was a 5, 6, 7, 8 or 9? Lets look at an example

Round the following number to 1dp Firstly, highlight the number to the first number after the decimal point So we have 9.2 But is this the answer? Now look at the number immediately after where we stopped highlighting If this number is a 5, 6, 7, 8 or 9 we increase the last digit by one. So 9.2 becomes 9.3

Round the following number to 1dp = 9.3 (1dp)

Rounding to the nearest whole number Is the arrow nearer to 6, 7 or 8? If it is halfway between, then round UP 6 7 8

Round these city populations to the nearest million Mexico City21.5 million Sao Paulo19.9 million Tokyo19.5 million New York15.7 million

Rounding to the nearest 10 Is the arrow nearer to 20, 30 or 40? If it is halfway between, then round UP

What is the volume of liquid to the nearest 10 millilitres ml

Rounding to the nearest 100 Is the arrow nearer to 400 or 500? If it is halfway between, then round UP

What is the mass of flour to the nearest 100g? Estimate the value to the nearest 10g flour grams

Rounding to 1 decimal place What value is the arrow pointing at? Is it nearer to 1.4 or 1.5?

Rounding heights & distances Round each of these winning heights & distances to the nearest whole number Round them to one decimal place (1 d.p.) Women’s events High Jump2.09 m Long Jump7.48 m Shot-put21.95 m Discus76.80 m Javelin80.00 m

Take Care! Round 3.48 to 1 d.p 3.5 Round 3.48 to the nearest whole number 3(not 4)