Addition/ Subtraction Fractions - Difficulty Level 1

At this level, problems involve fractions with different denominators and mixed fractions. A fraction is comprised of two parts: a numerator (the top number) and a denominator (the bottom number). For example, in the fraction 2/3, the "2" is the numerator and the "3" is the denominator. In order to add fractions, you must have a common denominator. A common denominator is a whole number that is a common multiple of the denominators of two or more fractions. For example, 12 and 24 are both common denominators for 3/4 and 5/6.

If the numerator of a fraction is less than the denominator, the fraction is called a proper fraction. If the numerator is equal to or greater than the denominator, the fraction is called an improper fraction. An improper fraction can be rewritten as a mixed fraction. For example, 5/3 is an improper fraction. It can be rewritten as 1 2/3, which is a mixed fraction.

Tutorial

Help the student use this step-by-step example to add the two mixed fractions with different denominators.

Solve: 3 1/5 + 6 4/9 = ?


Step 1: Rewrite horizontal problems vertically.

Step 2: Separate problem into addition of whole numbers and addition of fractions.

Step 3: Find a common denominator (a common multiple of the denominators of two or more fractions) for the fractions. For this problem, the common denominator is 45. Multiply 1/5 by 9/9. Multiply 4/9 by 5/5.

Step 4: Add the whole numbers (9). Add the fractions (29/45).

Step 5: Combine the whole number and fraction to produce the answer.

The correct answer is 3 1/5 + 6 4/9 = 9 29/45.

Now move on to subtracting two mixed fractions.

Solve: 7 4/5 - 3 2/9 = ?


Step 1: Rewrite horizontal problems vertically.

Step 2: Separate the problem into subtraction of whole numbers and subtraction of fractions.

Step 3: Find a common denominator (a common multiple of the denominators of two or more fractions) for the fractions. For this problem, the common denominator is 45. Multiply 4/5 by 9/9. Multiply 2/9 by 5/5.

Step 4: Subtract the whole numbers (4). Subtract the fractions (26/45).

The correct answer is 7 4/5 - 3 2/9 = 4 26/45.