RBM Math Unit 3 fractions lesson

1. Fractions Lesson: Measuring and Adding Fractions

2. Measuring FractionsMeasuring Fractions on a Tape Measure. Trades workers constantly read and measure fractions when using the Imperial system. Errors in measurements are costly both in time and money. Experienced trades persons measure twice and cut once. Trades workers work mostly in halves, fourths, eighths, sixteenths and occasionally, in thirty-seconds depending on the degree of accuracy required. It is important to be able to determine precise measurements on a tape measure.

3. Measuring FractionsMeasuring Fractions on a Tape Measure. The tape measure below identifies four fractions on an Imperial measuring tape. Understanding the measurements on a tape measure is very important to ensure quality work. Can you identify the measurements below? 2 3 4

4. Adding Fractions: 1 Step 1: Determine the common denominator. Do not change mixed numbers or whole numbers to improper fractions. Step 2: Add the numerators and place the answer over the denominator. Do not add the denominators. Add the whole numbers. Step 3: Express fractions in lowest terms

5. Adding Fractions:2Determine the total width of the three pieces of wood in the countertop. Step 1: Determine the common denominator for the wood pieces in the countertop below. 3 = 3 6 = 6 2 Step 2: Add the numerators. Place the number over the denominator. Add the whole numbers. 3 + 6 + 2 = 11 Step 3. Express the fractions in lowest terms. 11

6. Adding Fractions:3Determine the length of B in the construction drawing. Step 1: Determine the common denominator for the fractions found for measurement B. Common denominator is 8'-0" + 10'-6 " + 3'- " + 6'-0" Step 2: Add the numerators. Place the number over the denominator. Add the whole numbers. 8'-0" + 10'- 6 " + 3'- " + 6'- 0" = 27'- 6 " Step 3. Express the fractions in lowest terms. 27'-7