The test in the morning was to get you drilled in the basics of ruby. Refer back to it and make sure you practice as often as you can!
Today we looked at binary numbers and the way in which they work in discrete maths. We also touched on different number systems such as base-2, base-10 and base-16. Base-10 has 10 digits (0,1,2,3,4,5,6,7,8,9) and base-2 has 2 digits (0,1). Base-16 has a weird alphabet thing going on. The following was my working out to some of the day's challenges.
Convert 11201 from base 3 to decimal
3 * 4, 3 * 3, 3 * 2, 3 * 1, 3 * 0
81 27 9 3 0
1 1 2 0 1
81 27 18 0 1
=> 127Convert 103245 from base 6 to decimal
6 * 5 6 * 4 6 * 3 6 * 2 6 * 1 6 * 0
1 0 3 2 4 5
7776 1296 216 36 6 1
7766 0 648 72 24 5
=> 8525Convert 3123012 from base 4 to decimal
4 * 6 4 * 5 4 * 4 4 * 3 4 * 2 4 * 1 4 * 0
3 1 2 3 0 1 2
4096 1024 256 64 16 4 1
12288 1024 512 192 0 4 2
=> 14022Convert 123456 from decimal to base 2
2 ** 16 1
123456 -
65536
--
2 ** 15 1
57920 -
32768
--
2 ** 14 1
25152 -
16384
--
2 ** 13 1
8768 -
8192
--
2 ** 12 X 0
2 ** 11 X 0
2 ** 10 X 0
2 ** 9 1
576 -
512
--
64
--
2 ** 8 X 0
2 ** 7 X 0
2 ** 6 1
64 -
64
--
0
--
2 ** 5 X 0
2 ** 4 X 0
2 ** 3 X 0
2 ** 2 X 0
2 ** 1 X 0
2 ** 0 X 0
=> 11110001001000000