3.5.4 Convert integers between the bases specified in 3.5.3 (maximum 8
bits).
(Not teaching note for this one.)
Sample Question:
(a) Express the decimal number 78 in hexadecimal format. [1 mark]
JSR Notes:
***Video instruction link***
Well, it's right or it's wrong. So don't mess around with these sorts of questions, or be a "man" by trying to do them in your head. I'll say it again, this is consistently the kind of question that believe-it-or-not students screw up year after year. So slow down, concentrate, and do it right.
The tricks work, even if they seem elementary.
For binary/decimal, write down
128, 64, 32, 16, 8, 4, 2, 1
__ __ __ __ __ __ __ __,
For binary/hexadecimal, write down:
0000 0
0001 1
...
1110 E
1111 F
The trick to write these down without a careless error is to do it one column at a time, left to right:
8 zeros followed by 8 ones
4 zeros followed by 4 ones, twice,
2 zeros followed by 2 ones, four times,
1 zero followed by 1 one, eight times,
Make a mistake with this 20 second job, by saving 8 seconds and completing it in 12 seconds and you'll get 0 on the question. So, once again, don't rush.
And for hexadecimal to decimal and vice versa, you'll have the binary/hexadecimal chart written already, so why not use it, instead of doing the more difficult direct conversion.
And do note that you only have to convert to a maximum of 8 bits.
