Rounding To 1 2 or 3 Significant Figures
- Slides: 9
Rounding To 1, 2 or 3 Significant Figures
Significant Figures Important A significant number is any number that is not zero. Zero is only significant if it is surrounded by other numbers Numbers e. g. 0. 0001354 not significant 1. 0003658 significant
TOP TIP There should only be the number of significant figures asked for in the answer
Round to 1 significant figure Th 4 H 7 T 2 U 0 4720 thousands units tens hundreds 1) Count 1 significant figure and draw a line on the right 4720 2) Is the number on the right 5 or bigger? 3) YES, so round up Only 1 number 5000
Round to 1 significant figure U. 0. 0 1/100 0. 019 1/1000 1 9 units tenths decimal point thousandths hundredths 1) The 1 is the first significant figure, draw a line on the right of it 0. 019 2) Is the number on the right 5 or bigger? 3) YES, so round up Only 1 number 0. 02
Round to 2 significant figures Th 4 H 7 T 3 U 2 4732 thousands units tens hundreds 1) Count 2 significant figures and draw a line on the right 4732 2) Is the number on the right 5 or bigger? 3) NO, so round down Only 2 numbers 4700
Round to 2 significant figures U. 0. 2 1/100 0. 279 1/1000 7 9 units tenths decimal point thousandths hundredths 1) The 7 is the second significant figure, draw a line on the right of it 0. 279 2) Is the number on the right 5 or bigger? 3) YES, so round up Only 2 numbers 0. 28
Round to 3 significant figures Th 9 H 8 T 3 U 5 9835 thousands units tens hundreds 1) Count 3 significant figures and draw a line on the right 9835 2) Is the number on the right 5 or bigger? 3) YES, so round up Only 3 numbers 9840
Round to 3 significant figures T 1 U 8 . . 4 1/10 18. 43 1/100 3 tens decimal units point hundredths tenths 1) The 4 is the third significant figure, draw a line on the right of it 18. 43 2) Is the number on the right 5 or bigger? 3) No, so round down Only 3 numbers 18. 4