oneone SK-8 Objective: To use unit fractions to covert quantities from one form to another. Core Question: How can you convert metric quantities using unit fractions?? Drill: With your neighbor, come up with a strategy to solve the problem below. 22 tons = ___ dag

oneone SK-8 When converting between metric units, you can always move the decimal point to get the correct value. However, there are times when you have to convert from one system to another (metric to customary) or within an other system (i.e. time). In these cases a different system is needed because the units are not based on the number 10.

oneone SK-8 The method to be used is the Unit Conversion Method. This is based on the fact that any time you multiply a quantity by “1”, the value remains the same even if the form of the quantity changes. In this method you multiply the initial quantity by a specially chosen fraction (equal to 1 whole) that results in a new quantity with the desired units.

oneone SK-8 Example 2.5 feet = ____ inches 2.5 feet × 12 inches/1 foot = 30 inches (special form of “1”)

oneone SK-8 Let’s complete the drill. 22 tons × How can we convert tons? 1 ton = 2000 pounds

oneone SK-8 Let’s continue. 22 tons × = 44,000 pounds How can we convert pounds? 1 pound ≈ kg 2000 pound 1 ton

oneone SK-8 Let’s continue. 44,000 pounds × = 19,932 kg 22 tons = 19,932 kg How can we convert kg? 1kg = 100 dag kg 1 pound

oneone SK-8 Let’s continue. 19,932 kg × = 1,993,200 dag 22 tons = 1,993,200 dag x 10 6 dag 100 dag 1 kg

oneone SK-8 How about a couple more problems? 9.5 hours = _____ seconds hg = _______dg 27.8 L = ______ cm 3

oneone SK-8 Homework: 1.Unit Conversion Ditto (selected problems) 2. Study for Quiz.