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Binary Numbers
By Rania Kashi (P3223) on Monday, February 5, 2001 - 08:09 pm:

My friend told me that somewhere in the maths A level course, binary numbers are covered. Is this true? And then he left me with the following to try to crack: 111 010 010
He said that the following numbers should help me: 1,2,4,8,16,32 etc. Can someone show me the light on this one please, how do I use the clue he gave me?

Any help is most welcome!

By Oliver Samson (P3202) on Monday, February 5, 2001 - 09:13 pm:

I don't know if it's in the A level course, but I've seen it in earlier years, and it works as follows:

You may remember being taught in Primary school that in the normal system (decimal), the first column (working right-left) represents units, the second tens, the third hundreds etc. Binary is similar, but works in powers of two: the first is units, the second twos the third fours etc.

Therefore, 111 010 010

is equal to

(0×1) + (1×2) + (0×4) + (0×8) + (1×16) + (0×32) + (1×64) + (1×128) + (1×256)

which is 466. The highest digit is 1, as the number 2 would appear 10.