1. Unit 23 Mass or Weight Measurement

2. Basic Principles of Mass or Weight Measurement In the English or household system, the units for mass or weight measurement are ounces (oz) and pounds (lb). In the metric system, the base unit for mass or weight measurement is the gram (g). –At times, gram has been abbreviated as gm. This is no longer recommended because it could be confused for mg.

3. Converting Mass or Weight Measurements Conversion from one unit to another follows the same rules used in working with linear measurement. To convert between metric mass measurements and English mass measurements, follow the same rules used for linear measurement to convert English and metric measurements. –The easiest way to convert between English and metric measurements is to set up a proportion.

4. Mass or Weight Measurement Example: A newborn infant weighs 8 pounds (lb), 6 ounces (oz) at birth. How many kilograms (kg) does he weigh? –Convert the weight to ounces: (8 x 16) + 6 = 128 + 6 = 134 –Find an English-metric equivalent: 1 oz = 0.028 kg

5. Mass or Weight Measurement –Set up a proportion: –Multiply the means: 1 x X = X –Multiply the extremes: 0.028 x 134 = 3.752 –Write as means = extremes: 1X = 3.752 –The infant weighs 3.752 kg.

6. Practical Problem A box of examination gloves weighs 0.908 kilograms (kg). What is its weight in grams (g)?

7. Practical Problem One kilogram = 1,000 grams, so multiply: 0.908 x 1,000 = 908 The box of gloves weighs 908 g.