# Efficient ways of doing division calculations?

maths maths project skills
Recent activity on Dec 08, 2018
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There seems to be a number of methods for doing addition / subtraction / multiplication / percentage calculations more efficiently, whether that's mentally or on paper.

Are there any such methods for making division calculations more efficient? I can't seem to find any on YouTube or in PrepLounge.

I'm pretty accurate and speedy with the rest of the math requirements, but would like to brush up my division skills.

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Hey there,

A method I use a lot which works for generally more simple calculations: breaking down divisions into simpler parts. The key principle here is that it's easier to divide by small numbers - 2, 3, 5, 10.

The easiest is when the number you are dividing by is a square of two (4, 8, 16 ,32, etc.)

520 / 8 = 520 / (2 x 2 x 2) - so now, you just divide by 2 three times! 520, 260, 130

You can also do the same with dividing by 3.

380 / 6 = 380 / (2*3) = 190/3. Now to figure this out, find the closest multiple of three basically throuhg quick trial and error in your head. In this case, it's 180 = 3*60. if 180/3=60, then 190/3 is 60+(10/3), or 63.33

Finally, a tip to divide by 5: I always think of dividing by 5 as dividing by 10, multiplying by 2 (because 5=10/2). So for example:

740 / 5 = 740/(10)*2 = 74*2 =148.

This last trick with 50s of course also works with 50, 500, etc.

Hope this helps!

Hi,

The best thing - learn the division table up to 1/11 (i.e. 5/6 = 83.3%). It will help you calculate any percentage problems.

E.g. if your revenue is 530k and the market is 6.2.M, the market share is close to 5/6 and you can adjust depending on the numerator / denominator / zeros

Best

Some good advice already. Ultimately though, the answer is simple: practice, practice, practice. Use a software-based tool, or just do pages of divisions on paper. There is no secret, hard work is the key.