Divide by 5 in Seconds: A Simple Math Trick
Dividing by 5 can be a bit tricky, especially if you're trying to do it in your head. But there's a simple trick that can make it a breeze! This trick is based on the fact that dividing by 5 is the same as multiplying by 2 and then dividing by 10.
The Trick
Here's how it works:
- Double the number. For example, if you want to divide 15 by 5, double 15 to get 30.
- Divide the doubled number by 10. In our example, divide 30 by 10, which gives you 3. That's it! 15 divided by 5 is 3.
Why Does This Work?
Let's break down the math to understand why this trick works:
Dividing by 5 is the same as multiplying by 1/5.
Multiplying by 1/5 is the same as multiplying by 2/10 (since 2/10 simplifies to 1/5).
Multiplying by 2/10 is the same as doubling the number and then dividing by 10.
Example
Let's try another example. Let's say you want to divide 28 by 5.
- Double 28 to get 56.
- Divide 56 by 10 to get 5.6. So 28 divided by 5 is 5.6.
Practice Makes Perfect
The more you practice this trick, the easier it will become. You'll be able to divide by 5 in your head in no time!
Other Useful Math Tricks
There are many other cool math tricks out there that can help you with different calculations. Here are a few examples:
- To multiply a number by 9, multiply it by 10 and then subtract the original number. For example, 9 x 7 = (10 x 7) - 7 = 70 - 7 = 63.
- To quickly square a number ending in 5, multiply the tens digit by the next higher number and then add 25 to the result. For example, 25 squared is (2 x 3) + 25 = 625.
So next time you need to divide by 5, remember this simple trick and impress your friends with your mental math skills!