@mathematics.proofs 3 October 2020 edited more from that month

Financial Mathematics: How to Find the Percentage Change

*Image by* *Gerd Altmann* *from Pixabay* https://pixabay.com/users/geralt-9301/?utm_source=link-attribution&utm_medium=referral&utm_campaign=image&utm_content=1340649 In this article, I'm going to be demonstrating **how to calculate a** ****percentage change****. Since many of you reading this will be dealing with crypto cash, you may find this post useful. So, let's say for example your **one Bitcoin** is worth **£8,200**. Let's then say after a couple of days, its value rose to **£8,400**. What was the **percentage change**? Well, you had a **starting value** of £8,200. Let's call this **(x)**. You ended up with your starting value **(x)** plus the **percentage change** **(p)** multiplied by your starting value **(p*x)**. We'll call this **final value** (y). **x = starting value** **p = percentage change** **y = final value** In mathematical terms, your final value can be described as thus: **y = x + x*p = x*(1 + p)** Since you are only looking for the percentage change, you must isolate (p). Here are the steps to isolate (p): **y = x*(1 + p)** **1 + p = y/x** **p = (y/x) - 1** In ordinary words, the percentage change (p) should be: **Percentage Change = (Final Value / Starting Value) - 1** With this, you'd get a fraction which needs to be turned into a percentage that ****appeals to the human mind****. To **spice up** your final result, you can **multiply by 100**. So you could say that: **p = [(y/x) - 1]*100** Or in words... **Percentage Change = [(Final Value / Starting Value) - 1]*100**

Anyway, let me demonstrate how this would work in principle: Here are your values: **Final Value = £8,400** **Starting Value = £8,200** So, you could calculate the percentage change in this manner: **Percentage Change = [(£8,400 / £8,200) - 1]*100** Which is the same as: **p = [(y/x) -1]*100** Your result should be: **+2.44% (to 2 decimal places)** Now you can check this result and the power of the formula: **£8,200 * 2.44% = £200.08** The difference between £8,200 and £8,400 is **exactly £200**, so you can tell that the formula works. ****This is the beauty of financial mathematics****. ***Video related to this post (05.10.2020):*** https://youtu.be/fBoUf2DTzko *Article by Tiago Hands:* *https://www.instagram.com/tiago_hands* *Mathematics Proofs (Instagram):* *https://www.instagram.com/mathematics.proofs* *For mathematics articles:* *https://read.cash/@mathematics.proofs*