Multiply Fractions With Whole Numbers
Multiplying fractions with whole numbers is simple once you know how to put the whole number in fraction form. If you want to know how to multiply fractions with whole numbers, just follow these 4 very easy steps.
Steps
- Rewrite the whole number as a fraction. To rewrite a whole number as a fraction, simply place the whole number over 1.
- To rewrite 5 as a fraction, just write 5/1. 5 becomes the numerator, while 1 is the denominator; but the value remains the same.
- Multiply the numerators of the two fractions. To get the numerator of your answer, you simply have to multiply the numerator of the first fraction with the numerator of the second fraction.
- Multiply the denominators of the two fractions. To get the denominator of your answer, you simply have to multiply the denominator of the first fraction with the denominator of the second fraction.
- Multiply the denominators of 5/1 and 8/10 by multiplying 1 * 10. The answer is 10, so your new denominator will be 10.
- After multiplying the numerators and denominators of your fractions, your answer will be in fraction form, with the new numerator over the new denominator. The answer is 40/10.
- Simplify. To simplify a fraction, you have to write it in its lowest terms. You can do this by dividing the numerator and denominator by the same factor. In this case, both 40 and 10 are divisible by 10. 40/10 = 4 and 10/10 = 1, so your new answer is 4/1, or just 4.
- If your answer is 4/6, for example, you can simplify the fraction by dividing both the numerator and denominator by 2 to get 2/3.
Tips
- Typically, if the original problem is in a mixed number form, your answer should be a mixed number, and if the original problem is in improper fraction form, your answer should be in improper fraction or fraction form.
- Put the whole number before the fraction.
- Depending on your ultimate goal, you might leave improper fractions (in which the numerator is greater than the denominator, but the fraction doesn't cancel out to a whole number) in fraction form, or you might write them as mixed numbers. For example, 10/4 would reduce to 5/2 (after canceling 2 from both numerator and denominator). You could either leave 5/2 as it is, or write it as 2 1/2.
- You can perform a similar operation with mixed numbers. Convert the mixed number to an improper fraction, multiply as usual, then simplify (or not) according to your needs or the teacher's instructions.
