Question

Perform the following operations. Express your answer to the correct accuracy or precision warranted.
(a) 67.8 + 968 + 3.87
(b) 463.66 + 29.2 + 0.17
(c) 16.36 + 287.345 + 682.23
(d) 68.7 - 23.95
(e) 0.09875 - 0.0875
(f) 0.1927 - 0.035
(g) (2.6)(42.2)
(h) (65)(0.041)(325)
(i) (0.0060)(26)(55.1)
(j) (3.275 × 105)(1.0375 × 10-2)
(k) (1.625 × 10-3)(7.3 × 10-4)
(l) (3.9087 × 10-3)(4.920 × 107)

Answer 1

For example, in b), your answer would be 493.03, but when you add/subtract, the sig. fig. depends on the smallest amount of digits after the decimal in the problem (in this case, it would be 29.2<- so your answer would be 493.0)

When you multiply/ divide, the number of sig fig your final answer will have depends on the number with the least significant digits:
ex, g) =109.72 but no. of sig figs will 2 so it will equal \[1.1 \times 10^{2}\]

Answer 2

For clarification, because g) is 2.6 x 42.2 (2 sig fig vs. 3 sig fig) so your final answer will have the no. of the least no. of sig fig in your problem (n this case 2). Scientific notation makes it easier to express the correct no. of sig figs.