StephenM
22nd Mar 2001, 00:44
Sounds a daft subject I agree, but after sitting some of the maths tests for the recruitment schemes (BA more precisely) - I feel this is where I let myself down.
Does anyone recommend any texts or techniques or suggestions to help improve my mental arithmetic to get through these tests more confidently and accurately?
Already got "How to pass numeracy tests" by Tolley & Thomas
Any other suggestions?
WelshCityFlyer
22nd Mar 2001, 02:25
Play darts !!!!
Seriously, some oldies I've observed in the local pub, who play minus an electronic calculator, are whizzes at quick mental arithmetic. If you can master this, you can easily get re-aquainted with all the basics: decimals, long division, fractions, (even logarithms, etc...)
Eat your heart out, Carol Vorderman
WCF
It is true - practise makes perfect.
Just keep practising and practising and practising.
Jumbo Jockey
23rd Mar 2001, 22:26
Not a daft subject at all, mental maths causes a lot of people problems. Forgive me if I reproduce below in its entirety the advice I gave to teroc on the subject of time/speed/distance calculations a while back. Hope it helps.
The following explanation looks complicated, but follow it through slowly and practice it a few times, and you'll be doing d/s/t calculations in your head quickly before you know it:
Don't forget the big difference between written maths and mental maths: With pencil&paper/calculator handy, you're trying to reduce to a minimum the number of steps towards the final answer. In mental maths, whilst there is admittedly an element of time pressure, the trick is to break down the calculation into lots of small, easy, and easily memorable stages.
For example, at 190 kts, how much time to go 30 nm? In written maths, the calculation is 30 divided by 190 and then multiply by 60 to turn the answer into minutes, which is great if you have a whizz wheel or a calculator to hand, and indeed an autopilot to fly the aeroplane whilst you fiddle with them. Mentally, try and break the calculation down into manageable chunks. One useful trick to achieve that is to move decimal places around: 190 kts is 190 nm in 60 minutes, or 19 nm in 6 minutes or even 1.9 nm in 0.6 minutes if you really want to be pedantic. Since most people can also halve or double with reasonable accuracy, it's reasonably easy to say that the same 190 kts (or 19 nm in 6 mins) is also (doubling each time) 38 nm in 12 minutes, and 76 nm in 24 minutes. It's also (halving) 9.5 nm in 3 minutes. So your thought process to do the sum goes like this (and bear in mind we're not looking for tenth-of-a-second accuracy here, get within half a minute and you're doing well!
19 nm in 6 minutes is the first memory item. Halving the above gives 9.5 nm in 3 mins, which you have to hold in the brainbox long enough to add it to 19 in 6, making 28.5 nm in 9 mins, which is now the figure to remember. Only a mile and a half to find! Again, shift some decimals around: 28.5 in 9 mins is pretty close to 30 nm in 9 mins, or 3 nm in 0.9 mins, so why not halve that and call it 1.5 nm in roughly half a minute. Final score = 30 nm in about 9.5 minutes. (The answer by calculator is 9 minutes 28 seconds, which ought to be close enough for government work).
There's a lot more steps in doing it in your head like that, but each step isn't difficult and is also easily remembered for carrying forward to the next step in the calculation.
Like I said before, it sounds complex when you write it down, but read it through slowly and keep practicing and you'll find it works well.
Good luck!