1. Rounding To 1,2 or 3 Significant Figures

2. Significant Figures ImportantNumbers A significant number is any number that is not zero. Zero is only significant if it is surrounded by other numbers e.g. 0.0001354 1.0003658 not significant significant

3. TOP TIP There should only be the number of significant figures asked for in the answer

4. Round to 1 significant figure T 4720 UH 20 1) Count 1 significant figure and draw a line on the right 2) Is the number on the right 5 or bigger ? 3) YES, so round up 5000 7 hundreds Th 4 thousands units tens Only 1 number

5. Round to 1 significant figure 1/100 0.019 1/10001/10 19 tenths hundredths 0.019 1) The 1 is the first significant figure, draw a line on the right of it 2) Is the number on the right 5 or bigger ? 3) YES, so round up 0.02 0 decimal point U 0 units.. thousandths hundredths Only 1 number

6. Round to 2 significant figures T 4732 UH 32 1) Count 2 significant figures and draw a line on the right 2) Is the number on the right 5 or bigger ? 3) NO, so round down 4700 7 hundreds Th 4 thousands units tens Only 2 numbers

7. Round to 2 significant figures 1/100 0.279 1/10001/10 79 tenths hundredths 0.279 1) The 7 is the second significant figure, draw a line on the right of it 2) Is the number on the right 5 or bigger ? 3) YES, so round up 0.28 2 decimal point U 0 units.. thousandths hundredths Only 2 numbers

8. Round to 3 significant figures T 9835 UH 35 1) Count 3 significant figures and draw a line on the right 2) Is the number on the right 5 or bigger ? 3) YES, so round up 9840 8 hundreds Th 9 thousands units tens Only 3 numbers

9. Round to 3 significant figures 1/100 18.43 1/10 43 tenths 18.43 1) The 4 is the third significant figure, draw a line on the right of it 2) Is the number on the right 5 or bigger ? 3) No, so round down 18.4 8 decimal point U 1 units.. hundredths Only 3 numbers T tens