How to Multiply Fractions
A fraction is made of
Hi, my name is Bassem Saad and I'm a Math Ph.D. candidate at U.C. Davis, and I'm here today for About.com to show you how to multiply fractions.Now remember, a fraction is made of a numerator on top and a denominator on bottom. For example, in the fraction 3/4, three is the numerator and four is the denominator.Let's take a look at an example: 3/10 times 7/5. What you want to do is multiply across the top to get the numerator, and multiply across the bottom to get the denominator. So, three times seven is 21, and ten times five is 50.Let's take a look at another example: 7/15 times 3/4. We multiply across the top to get 21 in the numerator, and we multiply across the bottom to get 60 in the denominator. But if we look closely, we can see that the numerator and the denominator are both divisible by three. So we should simplify this fraction by dividing the numerator by three to get seven, and the denominator by three to get 20. So 7/15 times 3/4 equals 7/20.Let's talk practical applications; you may be wondering when you'll ever need to multiply fractions in your every day life. Well, architects need it to design structures, while construction workers need it to build those structures. Nurses and doctors need to know how to multiply fractions when determining dosages for patients. And you'll need to know how to do it if you plan on modifying a recipe.Thanks for watching, and to learn more, visit us on the web at About.com.