Question

how many significant figures are there in each of the following numbers? 35.21 0.028130 0.46 128.4

Explanation:

For 35.21:

Step1: Recall sig fig rules

Significant figures: non - zero digits are significant, and in a decimal number, all digits are significant. For 35.21, the digits 3, 5, 2, 1 are all non - zero and part of the number.
<Count the digits: 3,5,2,1>

Step2: Determine the count

There are 4 non - zero digits, and no leading/trailing zeros that are non - significant in this case. So the number of significant figures is 4.

For 0.028130:

Step1: Recall sig fig rules

Leading zeros (zeros before the first non - zero digit) are not significant. Non - zero digits and trailing zeros after a non - zero digit in a decimal are significant. For 0.028130, the leading zeros (0.0) are not significant. The non - zero digits are 2, 8, 1, 3 and the trailing zero after 3 is significant.
<Identify significant digits: 2,8,1,3,0>

Step2: Determine the count

Count the significant digits: 2, 8, 1, 3, 0. So there are 5 significant figures.

For 0.46:

Step1: Recall sig fig rules

Leading zero (0.) is not significant. The non - zero digits 4 and 6 are significant.
<Identify significant digits: 4,6>

Step2: Determine the count

Count the significant digits: 4 and 6. So there are 2 significant figures.

For 128.4:

Answer:

s:
35.21: 4
0.028130: 5
0.46: 2
128.4: 4