How to solve this problem

A step by step guide

Calculating percentage increase or decrease is a useful way to track data points over time. If you have two numbers, their relationship can be described by the percentage change between them. The reason this is an important metric is because it is normalized. Percentage increases and decreases can be slightly confusing at first, but become much more simple once you understand how they are calculated. To calculate percentage change, we will use three operations. As usual with percentage problems, these operations will involve basic arithmetic. In this case, we want to calculate the percentage increase or decrease from 9639 to 7942. Here are the steps:

Step 1: Subtract 9639 from 7942
The first step is to find the difference between the new number (the second input, 7942) and the old number (the first input, 9639). We can do this by simply subtracting 9639 from 7942: $$ 7942 - 9639 = -1697 $$

Step 2: Divide -1697 by 9639
The second step is to divide the result of step 1 by the original number. This is done to compare the difference to the original number. The equation for this is quite simply: $$ \frac{-1697}{9639} = -1697 \div 9639 = -0.17605560742816 $$

Step 3: Multiply -0.17605560742816 by 100
The final step of this calculation is to multiply the result of step 2 by 100 to turn it into a percentage (%). This equation for this is simple: $$ -0.17605560742816 \times 100 = -17.61 $$

And there you have it! These three steps can be used to calculate the percentage increase or decrease of any two numbers. Give it a try with another set of numbers.