Hi there. This is a quick and easy math guide on doubling numbers.

Add By Itself To Get The Double

You could do doubling as in multiplying a number by two but it is easier to double a number by add the number by itself.

Double of 20 for example is 40 as 20 + 20 is equal to 40.

Double of 8 is 16 from 8 + 8.

Working with larger numbers and doubling can be tricky. Double of 157 is 314. You could mentally break the number 157 into 150 and 7. Double of 150 is 300 and double of 7 is 14. Adding these separate doubles gives 314 as 300 + 14 is 314.

A more algebraic example would be doubling something like 3x. Double of 3x is 6x.

Extension - Double The Double To Get Four Times A Number

Using the fact that double of 2 is four, we can double a doubled number to obtain four times the original number.

Four times seven is 28. This is because double of 7 is 14 and double of 14 is 28.

The number 120 quadrupled is 480. Double of 120 is 240 and the double of 240 is 480.

Picture is from https://www.pexels.com/photo/brown-numbers-cutout-decors-1329295/.

Thank you for reading.