## Percentage Increase and Decrease

1. Use percentage strips to find a 50% increase of 424. Verify your solution using an equation.

10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% |

42.4 | 42.4 | 42.4 | 42.4 | 42.4 | 42.4 | 42.4 | 42.4 | 42.4 | 42.4 |

10% | 10% | 10% | 10% | 10% |

42.4 | 42.4 | 42.4 | 42.4 | 42.4 |

**Solution 1**: There are 15 values of 42.4 in 150%:

\[15(42.4)=636\]

**Solution 2:** 100% is 424. 50% (one-half) is 212. Therefore, 150% is 100% + 50%:

\[424+212=636\]

2. Use percentage strips to find a 40% decrease of 36. Verify your solution using an equation.

10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% | 10% |

3.6 | 3.6 | 3.6 | 3.6 | 3.6 | 3.6 | 3.6 | 3.6 | 3.6 | 3.6 |

**Solution 1**: To find a 40% decrease, we would subtract 40% from the total 100% which is same as subtracting \(4(3.6)\) from 36:

\[36-4(3.6)=36-14.1=21.4\]

**Solution 2:** Calculate directly by realizing that 40% decrease is the same as 60% of the total (100%\(-\)60%) which is:

\[6(3.6)=21.4\]

Return to Try This! (Percent Increase and Decrease).

### Watch (Solve Percent Problems using Double Number Lines)