Do Math Fast

Did you ever want to be able to do math in your head really fast? Here are a few tips. Unless you’re a mathematician, this should help.

Continue to work while you write.

As an example, If I’m calculating 4/68, while writing how many times 4 goes into 6 (part one), I’m already thinking about how many times it goes into 28 (that’s the next part).

Work with random numbers.

You’re driving in your car on route 82. Why not do as many calculations as you can with those numbers? Right now, I can think of 8+2, 8∙2, 8/2, 2/8, 8-2, 8^2, and 2^8. Though the last one might be a bit hard for now, you get the point.

Practice.

The bad news: This part is boring. The good news: You only need to practice for a minute a day. Personally, I use Brain Age2 for this. Anyway, all you need to do is use a random number generator, and solve the problems it gives you. Don’t have an RNG? Make one. (Steps at the end of my list)

This is a given. Obviously, it will help. Never use a calculator unless there is a time limit.

Memorize more times tables.

In school I learned the multiplication tables from 1∙1 to 12∙12. As a personal recommendation, I suggest learning from 1∙1 to 20∙20

Use familiar numbers

What is 14∙7? Give up? Try 7∙7, then multiply that by 2. You can use this trick on many numbers.

How to make a random number generator (This is easy):

1. Take a piece of paper and cut it into 9 pieces
2. Write the numbers 1 through 9 on those pieces of paper
3. Put them in a box, bag, etc
4. Do steps 1, 2 & 3 again
5. Cut a piece of paper into 4 pieces
6. Put +, -, X, and / on them
7. Put those in a box, bag, etc
8. Now, pull out one piece of paper from each container, do the calculation, and put them back in
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7 Responses to “Do Math Fast”
1. math geek Says...

On January 2, 2008 at 10:30 pm

i like it good idea… not many people have the time… one more tip i can give… try to put an image of what ever your doing in your head, and try to make it become real… if you can do this then you will become a mathematition and be able to do it all in your head.

good luck!

2. saif Says...

On April 18, 2008 at 10:28 am

give some other points

3. chinmay Says...

On August 22, 2008 at 7:05 am

its very simple

4. Ruben A. Palazuelos Says...

On October 8, 2008 at 2:57 pm

Here’s something I thought up while in traffic one day. Who doesn’t think about math while parked on the freeway? I’m certain this has been thought of and explained much better than I am about to attempt so I don’t really think it’s very groundbreaking, still a good helper none the less.

Let’s say you have 2 numbers you have to multiply that aren’t easy multiplication table numbers. For example 248 x 362. That work for you? Anyway as you can see these two numbers make most people want to grab a calculator. Well, not us my friends.

Step 1
Turn the numbers into rounder, easier to work with numbers. How? You might ask. Easily, by adding or subtracting to get there. For example if you add 2 to 248 you get 250 and if you subtract 2 from 362 you get 360. Now it is crucial that you remember what you added/subtracted from each number.

Step 2
Multiply the estimated numbers. Okay so 250×360= 90000 right? Good. You can remove the zeros for the multiplier and multiplicand and do 25 x 36 and then add 2 zeros to the end of the product of 900 to give you 90000 if you’d like.

Step 3
Add/subtract the “borrowed” amounts from each number. This is absolutely key. You have to do the opposite. We added 2 to 248 remember? Now you have to take that 2 and multiply it by 360. 2×360 = 720. Remember that since you added that 2 to 248 you will have to subtract 720 from the 90000. Now since you subtracted 2 from 360 you will have to multiply 2 and 248. 2×248 = 496. Now you’re going to have to add that to 90000 to get your final product.

Final step
Take your estimated product (90000) then subtract 720 and then add 496. Did you get 89776? Hope so. You can do this with as big a number as your brain can handle. Practice and you’ll be zipping through this in no time.

5. Lex luthor Says...

On February 15, 2010 at 3:35 pm

if you are trying to mutiply 2 digit number together, start from left to right, memorizing and adding the numbers in your head. Simple one like 12 x 12 is 120 plus 24,

the same for 3 dig numbers, just have to keep the placement of zeros the same and remember the numbers from left to right.

Reverse math!

No calulator is necessary

6. hate math its soo hard Says...

On October 21, 2010 at 7:26 pm

am looking for a way to this problem in my head:

(4 5/7 * 7 3/9) its realy hard for me pls help me any one?

i also wanna do it fast

7. poooooooop Says...

On February 14, 2012 at 7:04 pm

hi

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