Karen’s math review

Adding and subtracting fractions

Adding fraction with like denominators

If the denominator (the bottom number) is the same Add the numerators (the top number) Keep the bottom number the same Simplify your answer

example

Adding if denominators are different

If the denominator (the bottom number) is the different Find the LCM (least common multiple) of

the denominator Multiply the fractions by the factor that

will create common denominators Add the numerators (the top number) Keep the bottom number the same Simplify your answer

example

The LCM is 6 so multiply the first fraction The second fraction would

be multiplied by 2

Example continued

The two new fractions are

Since denominators are the same, add the numerators and keep the denominators the same and simplify

Subtracting fraction with like denominators

If the denominator (the bottom number) is the same subtract the numerators (the top

number) Keep the bottom number the same Simplify your answer

example

Subtracting if denominators are different

If the denominator (the bottom number) is the different Find the LCM (least common multiple) of

the denominator Multiply the fractions by the factor that

will create common denominators Subtract the numerators (the top

number) Keep the bottom number the same Simplify your answer

example

The LCM is 6 so multiply the first fraction by 3

The second fraction would be multiplied by 2

Example continued

The two new fractions are

Since denominators are the same, subtract the numerators and keep the denominators the same and simplify, if needed

Sample test

Solve1. 5/8-3/8=2. 4/3+3/43. 1 ¾+2 ¼4. 2 3/8-1 ½

Which is more5. 4/5 2/3

Sample test

Which is in lowest form6. 4/6 2/3 13/267. 8-2/38. 6/7+3/109. 2/3+210. ¼+1/2+1/411. What is 1st step in subtracting fractions with different denominators?

Sample test

12. What is the 3rd step in adding mixed numbers?

What operations sign will make these two equations correct?13. ½ ¼ =3/414. 3 1/3 1 5/6= 1 ½

What can you change to make this equation correct?15. ½ -1/3 =1

Sample testWrite two mixed number problems that will give you the

answer ½16.17.

What would happen if you subtract a fraction from a whole number?

18.Why does ¼+1/2 not equal 1/6?19.Draw and label a square whose perimeter is 1 inch.20.