Adding and Subtracting Fractions with Like …

1 Adding and Subtracting Fractions with like denominators Adding Fractions with like denominators To add Fractions they must have a common denominator. To add proper or improper Fractions with the same denominator: add the numerators together the denominator stays the same. Example: Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 1/11 Examples 82 + 83 = 85 A) 8 parts 8 parts 8 parts 2 shaded 3 shaded 5 shaded 82shaded 83shaded 85 shaded B) 216 + 2111 = 2117 21 parts 21 parts 21 parts += 6 shaded 11 shaded 17 shaded 216 shaded 2111 shaded 2117 shaded To add mixed numbers with the same denominator.

2 Add the whole numbers together add the numerators the denominator stays the same. 622 + 611 = 633 + = Examples A) 622 +611 633 reduce to lowest form = 213 B) 1614 +1653 + 166 16127 reduce to lowest form = 437 Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 2/11 Practice: Adding Fractions with like denominators 1. Use paper and pencil, fraction circles or other methods to demonstrate Adding the following Fractions and solve. Reduce answers to lowest forms.

3 The first two questions have been done for you. a) 1555154==+ b) 858283=+ c) =+248243 _____ d) =+103106 _____ e) =+9493 _____ f) =+126125 _____ g) =+142149 _____ h) =+6361 _____ 2. After painting her room, Maryann had 83 cans of burgundy and 84 cans of taupe paint left. How much paint in all did Maryann have left over? Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 3/11 3. At the end of the class pizza party, Frank tried to determine how much pizza was left. Each pizza originally had 8 slices. There was 1 slice of pepperoni left, 2 slices of Hawaiian and 3 slices of supreme.

4 In fraction form, how much pizza was left? 4. Jim needs 2 inches of ribbon to finish his project. He measured the three scraps of ribbon leftover and he had 31 inch, 85 inch and 43inch. How much ribbon does Jim have leftover? Does Jim have enough ribbon left over to finish his project? 5. Use paper and pencil, fraction circles, a calculator or another method to add the following. a) =+8184 b) =+721732 c) =+535114 d) =+93692 6. Fay made two pies for a picnic. 62 of her apple pie and 61 of her cherry pie were left. How much pie in total did she take home? 7. Jeff did schoolwork for almost one hour, as shown below. Review: 15 min 6015 Reading notes: 7 min 607 Practicing math: 20 min 6020 Show Jeff s total time for doing schoolwork in lowest fraction form.

5 Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 4/11 Subtracting Fractions with like denominators To subtract Fractions , they must have a common denominator. To subtract proper or improper Fractions with the same denominator: subtract the numerators the denominator stays the same. Examples A) 84 83 = 81 remove 3= B) 2015 2011 = 204 Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 5/11 =remove 11 To subtract mixed numbers with the same denominator: subtract the whole number subtract the numerators the denominator stays the same.

6 Examples 631611642= remove 1 whole and 61 221212= remove 21 Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 6/11 Special Cases of Subtraction Subtracting from 1 Fractions that have the same numerator and denominator represent one whole. Examples A) 144= B) 188= C) 1250250= 1 is one whole and can represent any fraction as needed. Examples A) 661= B) 771= C) 40401= To add or subtract Fractions , the same denominator is needed. A) To subtract 1 52, convert the 1 into the fraction 55. Examples 535255= B) To subtract 1 74, change 1 to the fraction 77.

7 737477= Subtracting from a whole number 2 or greater Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 7/11 A) To subtract , borrow 1 whole from 2. B) To subtract 875 , borrow 1 whole from 5. The borrowed 1 becomes the fraction66, because the denominator of 61 is 6. The borrowed 1 becomes the fraction88, because the denominator in 81 is 8. Examples 612 65161661= 81487884= Subtracting a fraction of greater value from a fraction of less value in mixed numbers Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 8/11 Examples A) B) Subtracting a whole number from a mixed number Subtract the whole number.

8 2 1 = 1 Subtract 0 from 21. 63is larger than 61, so 1 must be borrowed from 3. 63672 663 31642===322 Reduce to lowest form 72< (is smaller than) 74. Borrow 1 whole from 8. The borrowed 1 becomes 66 because 6 is the denominator. Add 676661=+. Subtract 7 3 = 4 The borrowed 1 becomes 77because 7 is the denominator. Add 797772=+. 74328 754743797 ==7 Subtract 7 3 = 4 Subtract 9 4 = 5 Example 1212 =211 Practice: Subtracting Fractions andMixedNumberswithLikeDenominators 1. Use paper and pencil, fraction circles, calculators or other methods to subtract the following. Reduce to lowest form. a) 7276 b) 1031010 c) 1231210 d) 125126 e) 142149 f) 6163 2. Tilly was working on a science project.

9 To manage her time, she divided her project into 9 parts. If Tilly has already completed 94 of her project, how much of her project, in fraction form, does she have left? Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 9/11 3. Kari usually takes 6040h to feed the chickens. Today she took only 6035h. How much extra time does Kari have? Show your answer in fraction form. 4. Use paper and pencil, fraction circles, a calculator or another method to solve the following. a) 754 732 b) 3 411 c) 613 2 d) 5110 549 5. Mr. Cardinal had 434cans of paint and used 413.

10 How much paint does he have left? 6. Judy was to run 856laps to train for a race. She ran825. How many laps does she need to run to complete her training? 7. Kalia brought 413packages of balloons to decorate the gym. When they were done, there was 43 of a package of balloons left. How many packages were used to decorate the gym? Knowledge and Employability Studio Mathematics Numbers: Fractions : Alberta Education, Alberta, Canada ( ) Adding and Subtracting Fractions with like denominators 10/11 8. Solve the following. Record each answer in a complete sentence and in lowest terms. 1. A bannock recipe calls for 432cups of flour. Robert added 411cups and then ran out of flour.