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 2399 to 380. Here are the steps:

Step 1: Subtract 2399 from 380
The first step is to find the difference between the new number (the second input, 380) and the old number (the first input, 2399). We can do this by simply subtracting 2399 from 380: $$ 380 - 2399 = -2019 $$

Step 2: Divide -2019 by 2399
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: $$ \frac{-2019}{2399} = -2019 \div 2399 = -0.84160066694456 $$

Step 3: Multiply -0.84160066694456 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: $$ -0.84160066694456 \times 100 = -84.16 $$

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.