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This is just something that occured to me today; I haven’t yet had the time to really explore it. Once I do, I’m fairly certain that it’s range of use will expand however, for the time being, please note the limitation listed below.
Technique for performing mental multiplication for larger numbers.
This applies to any natural number […]

Here’s a quick trick for mentally multiplying two numbers which are greater than or equal to 10 but less than 20.
Let’s use 18 and 19 as an example.
Add the second digit in one of the numbers to the other number.
18 + 9 = 27
Now, add a zero (mulitply by 10)
27 x 10 = 270
Multiply the […]