List of Measurable Verbs Used to Assess Learning Outcomes. Bloom's Taxonomy of Educational Objectives (1956): Cognitive Skills. A group of educators, led by Benjamin Bloom, identified a hierarchy of six categories of cognitive skills: knowledge, comprehension, application, analysis, synthesis and evaluation.
In normal maths, we don't use binary. We were taught to use our normal number system. Binary is much easier to do math in than normal numbers because you only are using two symbols - 1 and 0 instead of ten symbols - 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Computers use binary because they can only read and store an on or off charge. So, using 0 as off and 1 as on, we can use numbers in electrical wiring.
I'm not quite sure what the binary case is doing. What you seem to be trying to do is convert a string to a number and then get the hexadecimal string representation of that number. I'm not sure what you mean by using a string instead of just numbers. If you could explain that better, I should be able to help you.