### Home > CC1 > Chapter 4 > Lesson 4.1.3 > Problem 4-43

4-43.

Find each sum or difference without a calculator.

Find a common denominator.

To add the fractions together, start by finding the least common multiple of

and . Then use that number as a common denominator. This table lists multiples of and . LCM is

. Rewrite each fraction to have a denominator of by using Giant Ones, as shown below. Can you add the fractions now?

Whenever adding or subtracting decimals, be sure to line up the decimal points! It may help to write this problem like this:

Also, remember that the decimal point will fall in the same place in your answer.

. Rewrite as a fraction greater than one. Then follow the example in Part (a).