Revision Notes 2 for year 11

Today we had a look at questions 5b - 7 on your mock exam.

Question 5b

This was an expansion on the use of binary and hex.  The question was asking you to remember the link between binary and hexadecimal.  The link is that a nibble of binary maps exactly to a digit in hex.  

A nibble is a four digit group in Binary (half a byte).

You should remember how to create this table.  The pattern is worth learning.

Binary	Hexadecimal
0000	0
0001	1
0010	2
0011	3
0100	4
0101	5
0110	6
0111	7
1000	8
1001	9
1010	A
1011	B
1100	C
1101	D
1110	E
1111	F

Here is a rather long, but good explanation of the concept.

Why is it better?  Because if is easier to read for humans.

If you are asked to Explain something in an exam give two facts, or a fact and a reason.

Question 6

Question 6 was about databases, and logic.

fig 1 - Specification relating to required database knowledge

Question 6 asked you to recall information about relational databases.  Key words that came up in today's discussion were "entity", Table, and "truth table" when dealing with logic symbols.

Here is a quick explanation from catcomputerteacher.

Question 7

Question 7 asked us to recall information relating to programming.  The key words in the question were selection, and iteration.  You should be able recognize these statements written in pseudo-code, or code.

This is explicitly required by the syllabus;

fig 2 - from syllabus.  it is important to learn the meanings of these key words.

Summary

We are making good progress!  I know that I need to plan a lesson on databases. As there were a lot of gaps in your knowledge there, but we are making good progress towards success.  There is no rush, feel free to ask questions in class, or in the comments.