1. Metric Measurements and Conversions

2. Two terms to distinguish: Quantity : what one is actually measuring. Length: distance between points Volume: space sample occupies Mass: amount of matter in sample Time: how long action takes to occur

3. Unit: the calibrations to measure the quantity Inches Gallons Pounds Seconds There are many possible units to measure the same quantity.

4. Metric Units of Measurement Quantities Length Volume Mass Base Units Meter (m) Liter (L) Gram (g)

5. Prefixes are used in the metric system to alter the size of the base units. The meanings of the prefixes are all related to powers of 10.

6. Prefix Symbol Meaning Milli m1/1000 Centi c1/100 Deci d1/10 Kilo k1000

7. Interpret the prefix as some part or multiple of the base unit. For example: mL means 1/1000 of a liter (a part of) kg means 1000 of the grams (a multiple of) cm means 1/100 of a meter (a part of)

8. Conversions from one unit to another A single quantity can be measured in different units. It is possible to convert from one unit to another. The relationship between the units must be known to do this conversion. Kilo means 1000 so 1kg = 1000 g Milli means 1/1000 so 1000 mm = 1m

9. Convert the following: 45.6 kg = ? g The relationship between the units is used as a conversion fraction to solve the problem 1000g = 1 kg therefore: (45.6 kg) x (1000g) = 45,600g (1 kg)

10. Notice that the conversion fraction is set so the units given in the problem cancel with the units in the denominator. (1000g/1kg) instead of (1kg/1000g)

11. Let’s work one together 2,355 mL = _?_ L What is first step? (Determine relationship between units.) State relationship mL to L mathematically 1000 mL = 1 L What is next step? (Form conversion fraction) What is the conversion fraction? 1L / 1000 mL

12. What is the next step? Set up the problem and solve. How? 2355 mL X (1L / 1000 mL) = 2.355 L NOTE: fraction chosen so units cancel

13. Perform the following conversions in your groups at your table: 1.256 mg = _____ g 2.1864 m = _____ km 3.77.75 dL = _____ L 4.110 g = _____ kg 5.52.15 m = _____ cm

14. A multiple step problem can be used as well. 259 mm = ? dm Two steps: mm to m then: m to dm Relationships: 1000 mm = 1 m 10 dm = 1 m (259 mm) (1m/1000mm) (10 dm/1m) = 2.59dm

15. Solve the following: 475 cm = ? mm Steps = ?? Cm => m => mm Relationships = ? 100 cm = 1 m and 1000mm = 1m Set up problem 475 cm X (1m/100cm) X (1000mm/1m) =4750 mm