McCourt 2004

Objective

Be able to approximate numbers to a given

number of decimal places.

McCourt 2004

Round the following number to 1dp

6.348Firstly, 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.

McCourt 2004

Round the following number to 1dp

6.348 = 6.3 (1dp)

McCourt 2004

What if the red number was a 5, 6, 7, 8 or 9?

Lets look at an example

McCourt 2004

Round the following number to 1dp

9.2721Firstly, 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

McCourt 2004

Round the following number to 1dp

9.2721 = 9.3 (1dp)

McCourt 2004

McCourt 2004

Write the following numbers correct to 1 decimal place

1) 4.529

2) 17.583

3) 2.336

4) 0.0732

5) 0.8499

6) 32.6678

7) 12.40128) 0.078229) 143.427310) 2.305611) 9.788212) 1.4911

What about two decimal places? And three?