Week 6, 7 & 8 – Jss 1 First Term General Mathematics Lesson Notes

 WEEK 6        OPERATIONS ON FRACTIONS
ADDITION AND SUBTRACTION
Example 1: Find the value of the following (a) (b) (c)
Solution:
(a): = (since the denominator are the same we just add the numerator together)
(b): ) = ) (since the denominator are the same we just subtract the numerator from each other)
Try question C yourself
Example 2: simplify the following (a) (b) )
Solution:
(a)
(198 + 15 + 34)/24 = (find the L C m of the fraction then add the whole together, the L C M is 24)
= (247/24) = (convert the improper fraction to mixed numbers)
(b)
Solution:
(rearrange by separating the whole numbers from fractions)
=     (same denominator)
MULTIPLICATION AND DIVISION OF FRACTION
Example 1: Simplify the following (a) 4/5 * 2/3 (b) what is the product of 35/17, 2 5/6 and 4/8

1. 3/5 ÷ 4/9 (d) 24/5 * 56/8 ÷ 51/9

Solution:

1. 4/5 * 2/3 = 8/15( multiple the numerator and denominator together)
2. (b) what is the product of 35/17, 2 5/6 and 4/8 = 56/17 * 17/6 *4/8

   = 17 divides 17, 6 divides 56 also 4 divides 8
   = 14/3 = 42/3

    

3. 24/5 * 56/8 ÷ 51/9= 14/5 * 46/8 * 9/46(change to improper and also change the division sign to multiplication and also change the fraction up and down)

= 14/5 * 46/8 * 9/46 (46 divides 46 etc)
= 63/20 = 33/20
ASSIGNMENT
EXERCISE 5.9; NO 23, 24, 25, 33, 35, 36, 37 AND 40 PAGE 45
EXERCISE 5.12; NO 1, 2, 6, 7, 13 AND 14 PAGE 49