Add exercises testing understanding of number systems (#2)

This meets the learning objectives of the binary numbers section of
sprint 1.

Author: illicitonion

number-systems/README.md

@@ -0,0 +1,65 @@
+Do not use any tools or programming to solve these problems. Work it out yourself by hand, and fill in the answers.
+
+Do not convert any binary numbers to decimal when solving a question unless the question explicitly tells you to.
+
+The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.
+
+Convert the decimal number 14 to binary.
+Answer:
+
+Convert the binary number 101101 to decimal:
+Answer:
+
+Which is larger: 1000 or 0111?
+Answer:
+
+Which is larger: 00100 or 01011?
+Answer:
+
+What is 10101 + 01010?
+Answer:
+
+What is 10001 + 10001?
+Answer:
+
+What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
+Answer:
+
+How many bits would you need in order to store the numbers between 0 and 255 inclusive?
+Answer:
+
+How many bits would you need in order to store the numbers between 0 and 3 inclusive?
+Answer:
+
+How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
+Answer:
+
+How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
+Answer:
+
+Convert the decimal number 14 to hex.
+Answer:
+
+Convert the decimal number 386 to hex.
+Answer:
+
+Convert the hex number 386 to decimal.
+Answer:
+
+Convert the hex number B to decimal.
+Answer:
+
+If reading the byte 0x21 as a number, what decimal number would it mean?
+Answer:
+
+If reading the byte 0x21 as an ASCII character, what character would it mean?
+Answer:
+
+If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
+Answer:
+
+If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
+Answer:
+
+If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
+Answer: