# Rule 7: Different Faces of the Number 1

The number 1 can take on many forms. 4 - 3 = 1 and 10 - 9 = 1 can be used as a substitution for the number 1 because they have a value of 1. When the numerator of a fraction is equivalent to the denominator of a fraction, the value of the fraction is 1. This only works when you have a legal fraction; i.e., the denominator does not equal zero. You can substitute one of these fractions for the numer 1.

Example 1:

Example 2:

Example 3: According to Rule 1, is not a legal fraction because the denominator is zero. Therefore is undefined.

Example 4: The numerator is equivalent to the denominator.

Example 5: as long as .

### Work the following problems and click on Answer to check your results.

Problem 1: Find 9 x 1.

Problem 2: Find .

Problem 3: Write in three other ways.

Problem 4: Write in three other ways.

Problem 5: Write in three other ways.

Problem 6: Write 1 in three other ways.

Problem 7: Write 7 as a fraction in three ways.

Problem 8: Write -11 as a fraction in three ways.

Menu Back to Identification of Simple Fractions