 Pre-Algebra Practice Questions: Comparing Fractions Using Cross-Multiplication - dummies

# Pre-Algebra Practice Questions: Comparing Fractions Using Cross-Multiplication

Cross-multiplication is a handy tool for finding the common denominator for two fractions, which is important for many operations involving fractions. In the following practice questions, you are asked to cross-multiply to compare fractions to find out which is greater or less.

## Practice questions

1. Find the lesser fraction: 2. Among these three fractions, which is greatest: 1. Of the two fractions, Cross-multiply to compare the two fractions: Because 35 is less than 36, 2. Of the three fractions, Use cross-multiplication to compare the first two fractions. Because 21 is greater than 20, this means that 1/10 is greater than 2/21, so you can rule out 2/21. Next, compare 1/10 and 3/29 by cross-multiplying. Because 30 is greater than 29, 3/29 is greater than 1/10. Therefore, 3/29 is the greatest of the three fractions.