# Tina has 7/12 cups of bird food.  If her bird feeder holds 1/2 of a cup of bird food, how many times can Tina fill it?

pohnpei397 | Certified Educator

The answer to this question is that she can only fill the bird feeder once.

The way to figure this out is to find out how the two fractions (7/12 and 1/2) compare to one another.

One way to do this is to find out how many 12ths are equal to 1/2.  Once you know this, you will know how many times the bird feeder can be filled.

To find this out, you have to get to the point where the bottom number of the two fractions are both 12.

To do this, you have to figure out what to multiply 2 by to get 12.  Of course, this is 6.  So you multiply the top and bottom of that fraction by 6.

This tells us that 1/2 = 6/12.

So we know that it takes 6/12 cup of bird food to fill the feeder.  If you only have 7/12 cups available, you can only fill it once.

kristy5137 | Student

Tina can fill her bird feeder only once.

You can solve the problem by comparing the two fractions 7/12 and 1/2.

1)Find the LCD (Least Common Denominator)- in this case, the LCD would be 12.

2)Match the two fractions according to the LCD- you have to match 1/2 to the demoninator of 12, so you multiply the numerator and denominator by 6, which equals 6/12.

3)Compare results- From above, you found out 1/2 is equal to 6/12, which is just 1/6 less than the amount of bird food Tina has.

After filling the bird feeder once, Tina will have 1/6 birdfeed left, which is not enough to fill the bird feeder again.