need advice on math problems in aptitude test?

[flightsimmer747]

Hey guys,

Where can i get the best tips on handling numerical estimation, i mean i want to know how to properly multiply big numbers, decimal point in big numbers etc....

Can anyone shed some light on this part of the shl aptitude testing which i will soon undergo!

I understand its not something you can really study, but i also can't go in there not knowing simple logical reasoning to math problems, without being surprised and wasting time on trying to figure out how to do it.

We all learned it at some point so for the ones who can't remember all of that, i rather refresh my memory, i'm sure it will come to me but i need that little spark.

Thanks guys!
Any advice on the math portion will be greatly appreciated!

[bigfssguy]

I only finished 18 of 50 math questions on the test and i qualified for all 3 pools and did quite well on the test from what i was told. That was 6 years ago but i doubt it has changed much or even at all in that time. Just relax and do your best. My belief was that i would rather finish half and be right rather than finish them all and get none right.

[yrp]

Personally, I think is possible to prepare somewhat by practicing. Even when you are apt at something, the first question is going to take longer/more thinking than the 100th.

One trick for numerical estimation is to just look at the first digit or two. Eg mentally convert 121.45 x 71.22 to 120 x 70 --> 8400 ish. Then keep in mind whether you've rounded up or down, so that if they give you 8250 and 8650, you know which way to go (doesn't always work if you round up one number and down the other).

bigfssguy, maybe you are really good at numerical estimation, but less good at counting?

(ducking for cover)

[AuxBatOn]

Personally, I think is possible to prepare somewhat by practicing. Even when you are apt at something, the first question is going to take longer/more thinking than the 100th.

One trick for numerical estimation is to just look at the first digit or two. Eg mentally convert 121.45 x 71.22 to 120 x 70 --> 8400 ish. Then keep in mind whether you've rounded up or down, so that if they give you 8250 and 8650, you know which way to go (doesn't always work if you round up one number and down the other).

bigfssguy, maybe you are really good at numerical estimation, but less good at counting?

(ducking for cover)

What I do on those kind of test is as follow:

Round UP or DOWN both numbers to the nearest 10 (If I round one up, I'll also round the second one up) and multiply them together (like yrp did). That gives you an idea of the scale of the answer and if you can eliminate everything that is higher (or lower if you rounded up) than that, you know that this isn't the answer. Next, I multiply the last digits of the numbers to multiply. That gives me what the last number will be. For example :

Let's say we have 81.76 X 23.49. Let's say the choices are :

a) 1542.1854
b) 1597.1285
c) 1857.2476
d) 1920.5424

I'll round down to 80X20. That's 1600. That eliminates a and b. Now, if you multiply 9X6 (the last digits), that gives you 54, that means that the last digit of the answer will be 4. That eliminates b) and c). Therefore, the anwer is d).

AuxBatOn

[bigfssguy]

bigfssguy, maybe you are really good at numerical estimation, but less good at counting?

(ducking for cover)

If you can't impress them with intelligence dazzle them with Bulls*$t! Kinda been my motto for a loooong time

[flightsimmer747]

Sounds good, thanks, just need to constantly think that way now !

[flightsimmer747]

Any good tip for division and/or example 400% of 970689? It doesn't seem the same rule applies.

20% of 640678

etc...

[flightsimmer747]

Maybe i should pickup a text book and study it!

[Braun]

I was never really good at math, failed it twice in highschool. I found the mental math quite easy though (finishe 49 out of 50) trick is, like what everyone else said before, round up to what seems right, try using decimals to make a smaller number to multiply, but most importantly know that you'll most likely hardly ever get the right answer, the idea is to get as close to one of the answers and most of the time the answers are pretty different so you can get a good idea of the answer, but hardly ever the exact answer. I'd concentrate more on the stupid cube questions, arg.

[hydro]

Slight thread drift...

Speaking of those cubes. What are some of recommended ways to improve on that section? Any books or online sites that has more questions like that to practice?

hydro

[NJ]

You're already in! Why do you need cubes?

[flightsimmer747]

What cubes?

[NJ]

There is a link to the test questions here.

http://www.navcanada.ca/NavCanada.asp?L ... efault.xml

[flightsimmer747]

You mean spatial reasoning and 3d blocks mirrored etc....

Site did not work!

[NJ]

just go into the Nav Canada recruitment page. If you really want to find them, you will.

[flightsimmer747]

Any good tip for division and/or example 400% of 970689? It doesn't seem the same rule applies.

20% of 640678

etc...

My first thought upon reading your question:

10% of 640,678 = roughly 64,000

Double 64,000, and you get 128,000. (Actual answer = 128,135.)

As for answers on the test for a question like that, you'd probably see something like:

A) 12,813
B) 1,280,000
C) 128,135
D) 56,765

I spent about four seconds on the calculation there, and that's what they're looking for. By design, you will not have time to write out the answer on the scrap paper provided. What was it -- 10 minutes allowed for the 50 questions given? Maybe 15 minutes was alloted, can't recall. But it required a quick look, a stab at the answer, and then move on to the next one.

Be prepared for some fractional multiplication (and division? can't remember now) towards the end of the math section, i.e. 1/2 x 1/3 or 1/4 x 1/4...

I see, keep it simple and you won't get confused.

Although for fractions and decimals its alittle more diificult.