Given % change & amt. of change: Use Percent change=(amt of change)/(x) Do algebra steps to find x (original) Learnist Board: http://bit.ly/13AGhZq More information at http://bit.ly/ZXLw0I #P23

1. Percent Change Day 4:
Recovering the original and
new amounts.
If given the amount of change and percent change:
Use amount of change
Percent change
original amount
Then do the algebra steps to find the original amount.

2. Recall from
Day 1
In percent change situations, there are four numbers to pay
attention to:
1. Original amount (the “old”/“starting” amount before the
change)
2. New amount (the “ending” amount after the change)
3. Amount of change (the difference [subtract] between
original and new)
4. Percent change (percent increase or decrease).

3. Put the known numbers in the chart,
then figure out the others.

4. I consider the case
when the amount of change and the percent
change are given (and both the original and
new amounts are unknown) to be the
second of the two harder percent change
problem types.

5. Percent change is used in almost
every aspect of life to describe change
– and our world is changing!

6. Examples:
1. Profit for Wilson Manufacturing is up $2,400, which is
a 4% increase, compared to last year. What was the
profit last year and the profit this year?
amt. of change
Use Percent change =
original amt.
2400
.04
x
Do the algebra: .04x = 2400
2400
x
.04
Original amount x $60,000 (last year)
This year's profit = 60,000+2400 = $64,200

7. Examples:
2. The average number of turnovers during the second half
of the season was down 4.2 turnovers, which is a 35%
decrease. Find the turnover average in the first half of the
season and in the second half of the season?
amt. of change
Use Percent change =
original amt.
4.2
.35
x
Do the algebra: .35x = 4.2
4.2
x
.35
Original amount x 12 turnovers (1st half)
2nd half: 12 - 4.2 7.8 turnovers

8. Closing Notes
 Remember 
If given the amount of change and percent change:
Use amount of change
Percent change
original amount
Then do the algebra steps to find the original amount.

9. Stay tuned…
This is Day 4 of 4.
Learnist board:
http://bit.ly/13AGhZq