# 5th Grade - Multiply And Divide Fractions

 Grade Level: 5th Skill: Fractions, Percentages and Decimals Topic: Multiply and Divide Fractions Goal: Understand the concept of multiplication and division of fractions. Skill Description: Understand why when you multiply two fractions the answer is a smaller fraction than either number and why when you divide fractions you use the reciprocal of the second fraction

## Building Blocks/Prerequisites

### Sample Problems

 (1) 2/3 x 5/6? (5/9) (2) What is a reciprocal? (when you flip the fraction upside down and put the numerator on the bottom and the denominator on top) (3) Why do you have to use the reciprocal of a fraction when dividing? (4) 1/3 x ¾ (1/4) (5) ¼ divided by ½ (1/2)

### Learning Tips

 (1) Multiplying fractions is a breeze compared to finding common denominator for adding and subtracting. It’s almost a reward to do multiplication after spending months on “harder” fractions. (2) All answers must be in simplest form! Time after time students choose the wrong answer on the State test because their answer is not in simplest form. Simplifying must become habitual for your child. (3) This is the first year your child has been exposed to multiplying and dividing fractions. If they don’t “get it”, or seem to forget the process easily, remember that they will be retaught this standard in 6th and 7th grade. (4) Multiplying is really easy – just go straight across. 2/3 x 4/5 is 2x4 over 3x5 which is 8/15. No common denominators needed. (5) Division is almost as easy as multiplication – flip the second fraction (finding the reciprocal) and then multiply straight across. 2/3 divided by 4/5. Flip the 4/5 so it is now 5/4, then multiply 2x5 over 3x4 which equals 10/12. Don’t forget to simplify this into 5/6!

### Online Resources

 (1) (2) (3) (4)

### Extra Help Problems

 (1) ½ x 2/5 (1/5) (2) 7/10 x 1/3 (7/30) (3) ¾ x 2/3 (1/2) (4) 1/3 x ¼ (1/12) (5) ½ x 1/3 (1/6) (6) 2/4 x ½ (1/4) (7) 3/5 x 2/10 (3/25) (8) 2/7 x 4/5 (8/35) (9) 5/12 x ½ (5/24) (10) 5/9 x 2/3 (10/27) (11) ¾ x 4/5 (3/5) (12) 1/12 x ¼ (1/48) (13) 4/5 x 2/5 (8/25) (14) 1/8 x ¾ (3/32) (15) 3/8 x ½ (3/16) (16) ½ ÷ 1/3 (1 ½) (17) 4/5 ÷ 2/3 (1 1/5) (18) 1/6 ÷ ½ (1/3) (19) 5/9 ÷ ¾ (20/27) (20) 7/8 ÷ 1/3 (2 5/8) (21) 2/5 ÷ ¼ (1 3/5) (22) ¾ ÷ 3/7 (1 ¾) (23) ½ ÷ ½ (1 whole) (24) 6/10 ÷ 4/5 (3/4) (25) 5/8 ÷ 7/10 (25/28)