Comparing Rational Numbers Using Shortcut: Cross Multiply Lesson 4-2 10/11/16
How do you compare
rational numbers?
Video Link: https://www.youtube.com/watch?v=KNdUJQ_qd4U
*Remember use <, > or =
signs to compare
EX 1. Comparing
Fractions to Fractions
6/8 ___>___ 3/5
EX 1.
Cross Multiply.
Compare.
-9 3/12 __<__ -9 1/5
*Remember the negative value closest to zero would be the
greatest value.
EX 2. Comparing
Fractions to Decimals
5/8 _____ 0.35
EX 2.
Convert decimal to a fraction.
Simplify fraction(s) – If needed
Cross Multiply
Compare.
5/8 _____ 35/100
5/8 __>___ 7/20
EX 3. Comparing Percent
to Fraction
85% ______ 8/12
85/100 _____8/12
EX 3.
Convert percent to a fraction.
Simplify fraction(s)-If needed
Cross Multiply
Compare.
17/20 __>__ 2/3
Summary: When comparing fractions, which method do you like most? Explain.
Method A: Convert fractions to decimals then compare decimals
Method B: Find common denominators then compare numerators.
Method C: Use cross multiplying then compare the integers.