1. International System of Units (SI)

2. ► Measurement = # and unit  Ex: Miss. Pitre ran 10 km ► Base unit of length is the metre (m) ► “ “ “ mass is the gram (g) ► “ “ “ volume the litre (L) SI Handout SI Handout

3. Prefixes ► Part of word found before base unit  m = milli  multiply base unit by 1000  c = centi  “ “ “ “ 100  d = deci  “ “ “ “ 10  da = deca  divide base unit by 10  h = hecto  “ “ “ “ 100  k = kilo  “ “ “ “ 1000

4. Do the following 1. 983 m = _____ km 2. 72 g = _____ cg 3. 343 475 L = _____ daL 4. 8 349 m = _____ mm

5. Multiplication trick ► When multiplying by 10, 100, 1000…  Add as many zeros to the # as 10, 100, 1000.. has ► Ex: 356 x 1000 = 356 000  Move the decimal to the right by the # of zeros in 10, 100, 1000… ► Ex: 1.782 x 100 = 178.2 ► Do these:  3746 x 100 =  5.4345 x 1 000 000 =

6. Division trick ► When dividing by 10, 100, 1000…  Take away as many zeros to the # as 10, 100, 1000… has ► Ex: 175 000 ÷ 10 = 17 500  Move the decimal to the left by the # of zeros in 10, 100, 1000… ► Ex: 92 843.7 ÷ 10 000 = 9.28437 ► Try these:  42 635 ÷ 100 =  8 200 000 ÷ 100 000 =

7. Multiplying/Dividing by Decimals ► Multiplying by 0.1 is like dividing by 10 ► “ “ 0.01 “ “ “ “ 100 ► “ “ 0.001 “ “ “ “ 1000 ► Dividing by 0.1 is like multiplying by 10 ► “ “ 0.01 “ “ “ “ 100 ► “ “ 0.001 “ “ “ “ 1000

8. 1. 3874 x 0.01 = 2. 39.82475 ÷ 0.001 = 3. 435.456 x 0.1 = 4. 20 938 ÷ 0.1 =