Answer: 31 (a) 4 32 (a) 5
(b) 7 (b) 3
(c) 5 (c) 5
(d) 3 (d) 2
Significant Figures (sf) Rules:
1) Trailing zeroes are considered significant ONLY If a decimal point is provided.
2) Zeroes between the decimal point and number are NOT significant unless they are between numbers.
3) All digits in scientific notation are counted (disregard the exponent).
31 (a) 508.0 trailing zero so use rule 1 --> sf = 4
(b) 820,400.0 trailing zero so use rule 1 --> sf = 7
(c) 1.0200 x 10⁵ scientific notation so use rule 3 --> sf = 5
(d) 807,000 no trailing zeroes so use rule 1 --> sf = 3
32 (a) 0.049450 zero between decimal point & #, use rule 2 --> sf = 5
(b) 0.000482 zero between decimal point & #, use rule 2 --> sf = 3
(c) 3.1587 x 10 ⁻⁸ scientific notation so use rule 3 --> sf = 5
(d) 0.0084 zero between decimal point & #, use rule 2 --> sf = 2