Rules of Zeroes
1. Zeroes before a digit (1-9) do NOT count.
2. Zeroes in between digits DO count
3. Zeroes after digits without a decimal do NOT count
4. Zeroes after digits with a decimal DO count
Examples:
100 <- DO NOT count = 1 sig. fig.
100. <- DO count (decimal) = 3 sig. fig.
0.002 <- DO NOT count = 1 sig. fig.
0.0020 <- zeroes in front DO NOT count, but zero after the 2 COUNTS = 2 sig. figs.
YOU TRY!
1.) 102
2.) .000204
3.) 2,608,000
Answers:
1.) 3
2.) 3
3.) 4
Adding & Subtracting
1. Go by the lowest place holder or fewest digits after the decimal
Examples:
23.4
+ 2.33
___________
25.73 -> 25.7
10200
+ 5511.2
__________
15711.2 ->15,700
YOU TRY!!
1. 16 + 2.3
2. 20 - 0.008
Answers:
1.) 18
2.) 20
Multiplying & Dividing
1. Go by the lowest number of significant figures
Examples:
111*.02 = 2.2200 -> 2
500.0 * 35 = 17,500 -> 18,000 (you can only have to sig. figs. so you have to fill in the other place holders with zeroes. 18 is a lot different from 18,000)
YOU TRY!!
1.) 63.2 / 24
2.) 800 * 7.32
Answers:
1.) 2.6
2.) 6,000
1. Zeroes before a digit (1-9) do NOT count.
2. Zeroes in between digits DO count
3. Zeroes after digits without a decimal do NOT count
4. Zeroes after digits with a decimal DO count
Examples:
100 <- DO NOT count = 1 sig. fig.
100. <- DO count (decimal) = 3 sig. fig.
0.002 <- DO NOT count = 1 sig. fig.
0.0020 <- zeroes in front DO NOT count, but zero after the 2 COUNTS = 2 sig. figs.
YOU TRY!
1.) 102
2.) .000204
3.) 2,608,000
Answers:
1.) 3
2.) 3
3.) 4
Adding & Subtracting
1. Go by the lowest place holder or fewest digits after the decimal
Examples:
23.4
+ 2.33
___________
25.73 -> 25.7
10200
+ 5511.2
__________
15711.2 ->15,700
YOU TRY!!
1. 16 + 2.3
2. 20 - 0.008
Answers:
1.) 18
2.) 20
Multiplying & Dividing
1. Go by the lowest number of significant figures
Examples:
111*.02 = 2.2200 -> 2
500.0 * 35 = 17,500 -> 18,000 (you can only have to sig. figs. so you have to fill in the other place holders with zeroes. 18 is a lot different from 18,000)
YOU TRY!!
1.) 63.2 / 24
2.) 800 * 7.32
Answers:
1.) 2.6
2.) 6,000