Face it, you can’t ace aptitude tests without being comfortable with mathematical calculations. Each 30 seconds saved due to quicker calculation per question equals a total potential saving of 8-10 minutes, which translate to 4-5 additional attempts and better percentiles.

Candidates dread calculations commonly because of not being oriented towards doing calculations faster. I take the example of multiplying two three-digit numbers, 434*182.

Here are the different ways in which you can do this calculation,

Method 1

No doubt, this is absolutely correct, but it makes you write the numbers down on paper. Also, notice how your brain does the ‘right to left’ thinking here, something hardwired in us since childhood.

And that, is exactly what needs to change.

Start thinking from left to right instead.

Method 2

434 x 182 = (430+4) * (180+2) = [43*18 + 43*2] + [4*18 + 4*2]

Tip: Ignore the zeros.

43*18 = (40*18) + (3*18)

The remaining calculations are easy.

Of course, such a lateral change in approach will take time. I’d say at least 1-2 months. One way to learn this faster would be to just start multiplying and dividing numbers whenever and wherever you see them. I guarantee it’ll become second nature in no time.

Method 3,

434*182 = 434 * (200-18)

Here’s the interesting part. There’s just one multiplication here. And that is [434*2].

How? Here’s how,

434*18 = 434 * (20-2)

So, guess what 434 x 182 is,

434*2 followed by some addition and subtraction.

434*2 = 868

So, here’s what it is 86800- [8680-868] = 78988

It’s all about changing the mindset.

Hold On

There is an even better way.

Generally, in aptitude papers the answer options are spaced well apart. Because the question setters are expecting you to not make calculation errors, but logical errors. The options are selected based on what they think the candidate would arrive at, if they were to use incorrect logic. This last method won’t give you the exact answer, but the approximate answer, and in less than 5 seconds.

Method 4,

434*182 = 430*180 (approximately) + some more

= (400+30) * 180

= (4*18 + 3*18) * some zeros + some more

= (72 + 5.4) * some zeros + some more

= 77.4 * something

= 79 approximately = near-abouts of 79,000.

Most probably, the next closest answer would be +/- 10,000

That ‘some more’ will come intuitively to you, once you practice more and more calculations this way.

Hope this is helpful. ?

This article originally appeared on the blog of TestCracker, a website conceived by the most talented minds you can find, which is a no-nonsense zero-assumption and all powerful intervention in test preparation. Here’s the link.