MACHINE SHOP CALCULATION - OD1640 - LESSON 1/TASK 1
number divisible by 3.
No further division, therefore, is possible.
Step 5.
Multiply the divisors (5, 3, and 2) and remaining quotients (1,
1, 3, and 1). The result is the LCD.
LCD = 5 x 3 x 2 x 1 x 1 x 3 x 1 = 90
The new fractions are 72/90, 75/90, 70/90, and 81/90.
6.
Addition
a.
Finding the Sum of Two or More Fractions.
Rule 1.
To add together two or more fractions, first reduce them to
fractions having an LCD (discussed in paragraph 5f).
Then add the
numerators. Next, write the sum of these numerators over the LCD.
EXAMPLE (see figure 6 on the following page)
Add 1/4 + 1/3.
Step 1:
12 is the LCD of 4 and 3
Step 2:
1/4 = 3/12 and 1/3 = 4/12 3/12 + 4/12 = 7/12
b.
Finding the Sum of Mixed Numbers.
Rule 1. Find the LCD of the fractions. Add the whole numbers first. Then
add the fractions.
Add the sum of the fractions to the sum of the whole
numbers. If the sum of the fractions is an improper fraction, reduce it to
a mixed number.
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