Question

Perform the following operations (a)703 +7+0.66 (b)2.21 xx 0.3 (c) 12.4 xx 84

Answer 1

The following operations are:

• For operations, we must keep in mind the number of significant digits. After operation, our answer should be expressed with the significant digit equal to the least significant digit (after decimal point for addition and subtraction).
• (a) 703 + 7 + 0.66 = 710.66

            No. of significant digits in 703 after decimal = 0

            No. of significant digits in 7 after decimal = 0

            No. of significant digits in 0.66 after decimal= 2

            Answer = 711

• (b) 2.21 * 0.3 = 0.663

            No. of significant digits in 2.21 = 3

            No. of significant digits in 0.3 = 1

            Answer = 0.7

• (c) 12.4 * 84 = 1041.6

            No. of significant digits in 12.4 = 3

            No. of significant digits in 84 = 2

            Answer = 1000 = $1.0 * 10^3$