Personal Information
School Information
Reference Materials
Information for Students
Problem of the Week
Chaparral & New Mexico
Math Tutorial
Marvelous Math Links
Odds & Ends
Games and Gadgets
Fraction Calculator
Weekly Skills Quiz
Famous Matematicians
Student of the Month
Return to the Fraction tutorial page
To add fractions we must have the same denominator. If they are not the same it means we are trying to add different things. For example we cannot add a dime, (1/10 of a dollar, and a quarter (1/4) of a dollar, and get two of anything that makes sense.
We can, however add two quarters together since they are the same thing. 1/4 + 1/4 is the same as two quarters of 1/2 dollar.
Since we can't add fractions with different denominators we must find a way to make them the same if they are different. This is done by finding the Least Common Denominator. In the example above, the least common denominator for 1/4 and 1/10 is 20, since both 4 and 10 will divide evenly into 20 and it is the smallest such number.
Now that they have the same denominator we may easily add them.
Let's try adding 2/3 and 3/4 next:
Now try and do the problem below: You should get an answer of 1 1/6.
