RATL 1 | Lesson 2 | Try This! (Solutions Percent Increase and Decrease)

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

Watch (Solve Percent Problems using Double Number Lines)