How do you multiply fractions by whole numbers?

How to Multiply Fractions With Whole Numbers & Different Denominators

• Answer:

  Fractions are a common part of many math problems and represent a portion of something. For example, 1/4 is a fraction that represents one-fourth of one whole. Fractions can either be classified as proper, improper or mixed numbers. The number 1/4 is an example of a proper fraction. An improper fraction includes a numerator that is larger than the denominator, such as 9/5, and a mixed number contains a whole number and a proper fraction, such as 1 2/3. Difficulty: Moderately Easy Instructions Understand that you must convert mixed numbers to improper fractions. You cannot multiply mixed numbers without first changing them into improper fractions. For example, to multiply 1 2/3 and 4 1/5, you must change them before proceeding. Multiply the whole number by the denominator. Add the numerator to this number and place this number over the original denominator. This is the process used to convert a mixed number into an improper fraction. For 1 2/3, multiply 1 by 3; which is 3, then add the 2 to get 5. Place the 5 over the 3 to get an improper fraction of 5/3. Repeat this process with the other number to get the answer of 21/5. Multiply the numerators. The problem now looks like 5/3 x 21/5. These two numbers can be multiplied by beginning with the numerators. So 5 x 21 equals 105. Multiply the denominators: 3 x 5 equals 15. Simplify the fraction. Fractions should always be written in simplified form. Writing a fraction in mixed-number form is simplifying the fraction completely. The fraction is now 105/15, which is an improper fraction. To simplify, divide each number by 15, the greatest common factor. This leaves the fraction 7/1, which simplifies to 7. Tips & Warnings Tip: Never leave a fraction answer written as an improper fraction. Always convert to a mixed number if necessary.