Significant Figures & Scientific Notation

Significant Figures

• What do those words mean?– Important numbers

Significant Figures• What numbers are significant

• Always significant: – Numbers 1-9

• Sometimes significant– 0

• Significant 0– When between two significant numbers (709)– When decimal number ends in zero (8.50)

• Not Significant 0– When zero is just taking up space as a place holder (100)

Significant Figure Quiz

Write the number of significant figures each of the following numbers have1.0.007082.1,0803.10,000,000,0004.0.0100 5.893215.(Answer from the right) + 2.3

Significant Figure Quiz Answers

Write the number of significant figures each of the following numbers have1.0.007082.1,0803.10,000,000,0004.0.0100 5.893215.(Answer from the right) + 2.3 (8.2)

Significant Figures - Math

• When adding or subtracting– Look at the least common value (tenths, hundredths

• Examples:– 52.789 + 3.8 = ?– 16 – 4.350 = ?

Significant Figures - Math

• When adding or subtracting– Look at the least common value (tenths, hundredths

• Examples:– 52.789 + 3.8 = ?

52.789 Because the least common place+ 3.8____ value is tenths, you round your 56.589 answer to the nearest tenths

– Answer 56.6

Significant Figures - Math

• When adding or subtracting– Look at the least common value (tenths, hundredths

• Examples:– 16 – 4.350 = ?

16 Because the least common place− 4.350 value is the ones, you round your 11.650 answer to the nearest ones

– Answer 12

Significant Figures - Math

• When multiplying or dividing– Look at the least number of significant figures

• Examples:– 11.859 x 4.6 = ?– 24.859 ÷ 6.17 = ?

Significant Figures - Math

• When multiplying or dividing– Look at the least number of significant figures

• Examples:– 11.859 x 4.6 = ?

11.859 x 4.6 = 54.5514 Because the least number of (5) (2) (2) significant figures is 2, you’ll only

have 2 numbers in your answer

– Answer 55

Significant Figures - Math

• When multiplying or dividing– Look at the least number of significant figures

• Examples:– 24.859 ÷ 6.17 = ?

24.859 ÷ 6.17 = 4.0290113 Because the least number of (5) (3) (3) significant figures is 3, you’ll only

have 3 numbers in your answer

– Answer 4.03

Scientific Notation

• What is it?– A scientific way to write enormous or teeny

numbers

Scientific Notation

• What does it look like?– Coefficient: any number between 1 and 10– Base: x 10 (it will always be x 10)– Exponent: tells you how many times to move the

decimal point• Positive expenent = move to the right• Negative exponent = move to the left

Scientific Notation

• You need a coefficient, base, and exponent• Examples:– 5,040,000,000,000,000 = ?– 0.000000000000016 = ?

Scientific Notation

• You need a coefficient, base, and exponent• Examples:– 5040000000000000 = ?

Answer: 5.04 x 1015

– 0.000000000000016 = ?

Answer: 1.6 x 10 -14

Scientific Notation

• You need a coefficient, base, and exponent• Examples:– 8.23 x 1014 = ?– 1.25 x 10-9 = ?

Scientific Notation

• You need a coefficient, base, and exponent• Examples:– 8.23 x 1014 = 823000000000000.

Answer: 823,000,000,000,000

– 1.25 x 10-9 = 0.00000000125

Answer: 0.00000000125

Homework

• Significant Figures & Scientific Notation WS (Front & Back) (Due Tomorrow)