Up next in Basic Math Skills (15 videos)
Do you and arithmetic add up to disaster? Sharpen your basic bath skills with the lessons in this Howcast video series.
You Will Need
- Two fractions
- A pencil and paper
Add fractions with same denominator
Add or subtract the numerators and keep the same denominator if the fractions have the same denominator.
Find a common denominator
Find the lowest common denominator to both fractions if they have different denominators. For example, if you add 1/3 plus 3/8, the least common denominator is 24, since three times eight equals 24.
Rewrite the fractions
Rewrite the fractions, using the lowest common denominator. Multiply the numerator by the same number by which you multiplied the denominator.
Add or subtract the numerators
Add or subtract the numerators and write the sum over the common denominator. The sum of 9/24 and 8/24 is 17/24. The difference is 1/24.
Reduce the fraction
If necessary, reduce the fraction by dividing the numerator and denominator by the highest number you can.