5th Grade - Add And Subtract Mixed Numbers

 
     
 
     
 
Newsletters:
 
     
 
 
5th
Fractions, Percentages and Decimals
Add and Subtract Mixed Numbers
Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form.
This is a very large standard that takes many months to teach. Students typically begin reviewing simplifying fractions, converting mixed numbers to/from improper factions and adding and subtracting fractions with like denominators. They continue learning how to add and subtract fractions and mixed numbers with unlike denominators and are expected to solve all problems in their simplest form
 

Sample Problems

(1)

3/10 + 5/10 (4/5)

(2)

1 and 9/12 +5 and 1/12 (6 and 5/6)

(3)

6 and 1/3 +2 and 9/10 (9 and 7/30)

(4)

5 and 1/6 – 2 and 5/6 (2 and 1/3)

(5)

9 and 2/3 – 7 and ¼ (2 and 5/12)

Learning Tips

(1)

At the top of your child’s paper he/she should write Whole number = big number, numerator = top number, denominator = bottom number. Labeling the parts will increase understanding in word problems, and get your child more comfortable with the vocabulary

(2)

On all State tests answers are written in simplest form. If your child can’t “find the answer” in one of the multiple choice questions, chances are that they have not simplified their answer. For example, 3/10 + 2/10 = 5/10, but none of the choices are 5/10. The correct answer is ½, because the answer needs to be simplified.

(3)

If your child is struggling to find a common denominator, have them make a list of the multiples of each denominator on the side of the paper. For example, if the two denominators are 4 and 6, your child should make a list to find which number they both have in common–

  1. 6

  1. 12

12 18

(4)

Most adults have tricks or shortcuts to solving fraction problems. Avoid teaching your child tricks because it puts more emphasis on the correct answer and not on understanding the process. In elementary school they need to learn the foundations, so that later on the “tricks” make sense.

(5)

2 3/8 – 1 5/8 is going to be a tricky problem for your child. They will instinctively want to switch the order of the numbers because 5 (numerator) is larger than 3(numerator) so you can’t subtract. Remind your child that any number over itself (8/8) is 1. Borrow from the 2 by adding eight more to your numerator (8+3=11) Rewrite the problem as 1 11/8 – 1 5/8, then do the work.

Extra Help Problems

(1)

1/3 + 1/3 (2/3)

(2)

4/10 + 7/10 (11/10=1 and 1/10)

(3)

9/12 – 1/12 (8/12=2/3)

(4)

2/5+3/5 (5/5 = 1 whole)

(5)

7/10 – 6/10 (1/10)

(6)

5/12 – 1/12 (4/12 = 1/3)

(7)

1 2/3 + 3 2/3 (4 4/3 = 5 1/3)

(8)

7 9/12 + 7 2/12 (14 11/12)

(9)

4 1/5 + 3 2/5 (7 3/5)

(10)

7 5/6 – 2 2/6 (5 ½)

(11)

5 7/12 – 3 5/12 (2 1/6)

(12)

2 ¾ - 1 ¼ (1 1/2)

(13)

½ + ¾ (1 ¼ )

(14)

2/5 + 4/6 (1 1/15)

(15)

1/3 + ¼ (7/12)

(16)

5/6 – 2/12 (2/3)

(17)

2/3 – 4/6 (0)

(18)

7/8 – 1/5 (27/40)

(19)

2 3/10 + 1 1/5 (3 ½ )

(20)

6 ¼ + 2 2/3 (8 11/12)

(21)

7 ½ + 3 3/5 (11 1/10)

(22)

8 1/3 + 8 ½ (16 5/6)


(23)

2 ¾ - 1 1/12 (1 2/3)

(24)

5 6/10 – 2 4/5 (2 4/5)

(25)

7 ½ - 3 2/5 (4 1/10)

newsletters

 

Related Games

 
 

Copyright ©2009 Big Purple Hippos, LLC