Addition and Subtraction on Improper Fractions

Addition and Subtraction on Improper Fractions Addition: 12+35 Finding L.C.M. as 10. L.C.M.→Least Common Factor Now ,we get 12𝑋55=510 35𝑋22=610 Addition of these two fractions → 510+610=1110 Another method of addition is as follows: 12+35 1X5=5 2X3=6 2X5=10 510+610=5+610=1110 We can easily find out the L.C.M of some numbers as follows: L.C.M. of 2 numbers which have only ‘1’ common factor : For Example:  2 and 3 = 6  3 and 4 =12  3 and 5 =15 Try these also. L.C.M. of  2 and 5 = 10  3 and 7 = 21  6 and 5 = 30  8 and 3 = 24  5 and 7 = 35  8 and 9 = 72  7 and 4 = 28 L.C.M. of 2 numbers when one number ia a factor of another number : For Example:  2 is a factor of 4 L.C.M. of 2 and 4 = 4 (the bigger number)  3 is a factor of 9 → L.C.M. of 3 and 9 = 9  5 is a factor of 15 L.C.M. of 5 and 15 =15 Try these also. L.C.M. of  2 and 6 = 6  2 and 8 = 8  4 and 8 = 8  3 and 12 = 12  7 and 49 = 49  6 and 12 = 12  7 and 14 = 14  9 and 81 = 81  10 and 100=100 Let us see the another problem: 35+23+715 Now we can easily find the L.C.M of these numbers as 15 Then we get, 35𝑋33=915 23𝑋55=1015 715𝑋11=715 When we add these fractions as follows: 915+1015+715=9+10+715=2615 Another Method : 35+23+715 3X3=9 5X2=10 5X3=15 915+1015+715=9+10+715=2615 Subtraction: 86− 35 L.C.M of 6 and 5 is 30. 86𝑋55=4030 35𝑋66=1830 4030−1830=40−1830=2230 Another method: 86− 35 8X5=40 6X3=18 6X5=30 4030−1830=40−1830=2230 Let us see the another problem: Subtract: 78−23 78𝑋33=2124 23𝑋88=1624 → 2124−1624=1524