1. III. Unit Conversions SI Prefix Conversions Dimensional Analysis
Measurement
III. Unit Conversions
SI Prefix Conversions
Dimensional Analysis

2. A. SI Prefix Conversions
1. Find the difference between the exponents of the two prefixes.
2. Move the decimal that many places.
To the left
or right?

3. A. SI Prefix Conversions=
532 m = _______ km
0.532
NUMBER
UNIT
NUMBER
UNIT

4. A. SI Prefix Conversions
Symbol
Factor
mega- M
106
kilo- k
103
deci- d
10-1
centi- c
10-2
move left
move right
milli- m
10-3
micro- 
10-6
nano- n
10-9
pico- p
10-12

5. A. SI Prefix Conversions
0.2
1) 20 cm = ______________ m
2) A = ______________ mA
3) 45 m = ______________ nm
4) 805 dm = ______________ km 32
45,000
0.0805

6. B. Dimensional Analysis
The “Factor-Label” Method
Units, or “labels” are canceled, or “factored” out

7. B. Dimensional Analysis
Steps:
1. Identify starting & ending units.
2. Line up conversion factors so units cancel.
3. Multiply all top numbers & divide by each bottom number.
4. Check units & answer.

8. B. Dimensional Analysis
Lining up conversion factors:
= 1
1 in = 2.54 cm
2.54 cm cm
1 =
1 in = 2.54 cm
1 in in

9. B. Dimensional Analysis
Your European hairdresser wants to cut your hair 8 cm shorter. How many inches will he be cutting off? cm in
8 cm
1 in
2.54 cm
= 3.15 in 

10. B. Dimensional Analysis
How many milliliters are in 1 quart of milk? qt mL
1 qt
1 L
1.057 qt
1000 mL
1 L
= 946 mL

11. B. Dimensional Analysis
5) Assume your mass is 55 kg. How many pounds do you weigh? kg lb
55 kg
2.2 lb
1 kg
= 121 lb

12. B. Dimensional Analysis
6) How many feet long is a 5K (5 km) race? km ft
5 km
1 mi
1.609 km
5280 ft
1 mi
= 16,408 ft

13. B. Dimensional Analysis
7) How many grams does a 10-lb. bag of potatoes weigh? lb g
10 lb
1 kg
2.2. lb
1000 g
1 kg
= 4545 g

14. B. Dimensional Analysis
8) Taft football needs 550 cm for a 1st down. How many yards is this? cm yd
550 cm
1 in
2.54 cm
1 ft
12 in
1 yd
3 ft
= 6.01 yd

15. Scientific Notation
Way to write large numbers in shorthand by writing zeros as multiples of 10 or 1/10.
3.5 × 106
Rewrite the first number 3.5
Then read the exponent on the 10
If the exponent number is positive, move the decimal place that many places to the right.
Answer:

16. Scientific Notation 3.5 × 10-3
If the exponent is negative, move the decimal that many places to the left.
Answer:

17. Scientific Notation 38000 and 0.00584
Move the decimal until the number is less than 10 but greater than 1, then write that number.
If you moved the decimal to the right add
× 10-number you moved
If you moved the decimal to the left add
× 10+number you moved
Answers:

18. Changing quantities into scientific notation
5,453,000 m
Answer:
300.8 kg km

19. Changing quantities into scientific notation
332,080,000 cm
Answer:
34,800 s ng