MATHEMATICS YEAR 4 FRACTIONS NOTES (ADDING & SUBSTRACTING)
FRACTION: HOW TO ADD?? When the denominators are the same… We have a rectangle that is cut into 4 pieces... Each piece is and 2 pieces are If we add , that would be… 4 4 + = 1 4 2 4 1 2 + = 3 4
When the denominators are different… We need to find least common denominator (LCD) For example, The LCD for 2 and 3 is 6… Change : Change :
When the denominators are the same… We have a rectangle that is cut into 6 pieces... Each piece is . So, HOW TO SUBTRACT?? (5 pieces) Take away 2 pieces, So, (3 pieces are left) 1 6 5 6 - 2 6 5 6 = 5 6 - 2 6 = 3 6
When the denominators are different… When the denominators are different…
FRACTIONS TASK : PROBLEM SOLVING (ADDING & SUBSTRACTING)
Sally ate ⅛ of cake and her sister ate ⅜ of it. What fraction did they eat altogether?
Arif mowed 3/10 of the lawn and Tina mowed 5/10 of the lawn. How much of the lawn has been mowed?
3. May planted 1/3 of her vegetable garden in the morning and another 1/3 of it in the afternoon. What fraction of her garden was planted in one day?
Jill studied math for 2 3/4 hours and Spanish for 1 2/3 hours. What was her total study time?
Ashley made a muffin. She used 1 2/3 cups of white flour and 3 cups of whole-wheat flour. How much flour did she use in all?
Sidhu had 8 dollars. He spent ⅝ of his money on candy and another ¼ of his money on soda. What fraction of his money did he spend altogether?
Maria collects 1 ¼ boxes of litter from the roadside. Amy collects 2 ¾ boxes. How many boxes of litter did they collect in all?
There are seven pieces of pizza. Roy ate 3/8 of the pizza for dinner. He ate 3/8 of the pizza for a bedtime snack. How much of the pizza is left?
Miss Lee brought 4 4/5 pounds of candy to school. The students in third grade ate 2 ½ pounds of the candy. How much did Miss Lee have left?
A plumber needs 8 ¾ metres of pipe to repair a water line. He has only 4 ½ metres of pipe. How many more metres of pipe does he need?
Adam bought 2 1/5 pounds ground beef. His mother used 1 3/5 pounds to make hamburgers. How much of the ground beef was left?
All of William's school books weigh a total of 5 1/2 kilograms. If he take away his math book, the total weight drops to 2 1/2 kilograms. How much does William's math book weigh?