Module 2 Pretest Homework Packet   Answers

Module Two-Part B: Rounding Off & Arithmetic Operations of Sign. Figures     5 points

Round off the following numbers to three significant figures:

(1) 1.598 x 106 =   ___1.60 x 106 _

(2) 0.000 000 484 500 = __0.000 000 485 ___or__4.85 x10-7_

(3)  0.01045  =  __0.0105 __or__1.05 x 10-2____

(4)  1.98754 X10-7 =  __1.99 X10-7 ________

Perform the following addition/subtraction/multiplication/division operations and express the answer using the proper units and significant figures:

(5)    4        mL

16.3     mL

+     0.953 mL

21.253 mL = 21 mL

(6)   376.5  mL

-   76     mL

300.5  mL = 301 mL

(7)    16.5 cm

X   1.7 cm

28.05 cm2   = 28 cm2

(8)       12.0  g ÷ 1.00 g =  12.0

or

12.0  g / 1.00 g =   12.0

(9)  9.2 cm  X  9.20 cm  X  3.14 X  22.65cm  =  6019.68 cm3  = 6.0 x 103 cm3

(10)  (5398 cm3 – 2060.2 cm3) /16.8 cm3/sphere  =   3338 cm3 / 16.8 cm3/sphere =

198.69 spheres = 199 spheres

Additional Homework (not required) for your practice:

Corwin 7th edition:

Page 25:  #15-#18;  #19-#22; #23-#26