Computer Science

Easter homework

DUE the first lesson back after the break!!!!!

Programming practice

To become familiar with the programming language

Complete the practice python programming tasks on code academy

http://www.codecademy.com/learn

A great book to learn to program:

http://files.swaroopch.com/python/byte_of_python.pdf

If you have any difficulties please feel free to contact:

p.morris@montomeryschool.co.uk

l.harwood@montgomeryschool.co.uk

Richard.west@go.edgehill.ac.uk

As well as using Montgomery high school on google + or @montyict on twitter

Theory Revision

Data Types

Boolean True /false

String It is hot outside

Integer 457

Floating Point 3.548

What data type is counter?

Please define the following

Variable

Iteration

Algorithm

Syntax error

Network Topology

Network topology refers to how computers are connected to a

network. There are three main types of network topology: bus, ring

and star.

The bus network In a bus network all the workstations, servers and printers are joined

to one cable (the bus). At each end of the cable a terminator is

fitted to stop signals reflecting back down the bus.

The ring network In a ring network each device (workstation, server, printer) is

connected to two other devices, this forms a ring for the signals to

travel around. Each packet of data on the network travels in one

direction and each device receives each packet in turn until the

destination device receives it.

The star network In a star network each device on the network has its own cable that

connects to a switch or hub. A hub sends every packet of data to

every device, whereas a switch only sends a packet of data to the

destination device.

Pick one of the topologies and research their advantage and

disadvantages as well providing a drawing of a typical layout.

DECIMAL BINARY CORRECT?

0

8 4 2 1

1

8 4 2 1

2

8 4 2 1

3

8 4 2 1

4

8 4 2 1

5

8 4 2 1

0 1 0 1

Example

6

8 4 2 1

7

8 4 2 1

8

8 4 2 1

9

8 4 2 1

10

8 4 2 1

Binary Numbers

Binary means two. All

numbers in binary are

made up of either a 0 or a

1.

To work out a decimal

number we use a grid like

the ones on a left.

Decimal number 5

Is there any eights in five?

NO! so a zero goes in the

eight column.

Are there any fours in 5.

Yes so we put a 1 in the

four column.

Leaving one!

So we out the one in the 1

column and not the two

column

Now work out the binary

numbers for the other

questions.

Flowchart

Create a flowchart which demonstrates the process of ordering a meal at a fast food restaurant.

Database / SQL

Table = Menu

Meal-code Name Price Meal-deal

1001 Fish Fingers 1.99 No

1002 Hot Dogs 2.85 No

1003 Turkey Burgers 2.19 No

1004 Jacket Potato 2.50 Yes

1005 Chicken Korma 3.25 No

Which of the above would be the primary key?

The following SQL statement has been executed to the database table

above what would happen?

SELECT Name, Price, Meal-deal

FROM Menu;

Where Meal-code = 1004;

Data Structures (revision only)

The study of data structures is about organising data so that it is suitable

for computer processing. Computer hardware looks at storage devices

like internal memory and disks as holders of elementary data units

(bytes), each accessible through its address (usually an integer).

Defining data structures

A data structure can be defined as a collection of different data

elements, which are stored together in a clear, structured form.

In programming, one of the most important design decisions involves

choosing which data structure to use. Arrays and linked lists are among

the most common data structures and each is applicable in different

situations.

Data structures: arrays

There are situations during the writing of code when programmers need

to hold related data as a single item, for example a list of employees’

names or makes of car. One method of doing this would be to assign a

variable to each item in the list.

One-dimensional arrays

A one-dimensional array in Python and PHP is a data structure that

allows a list of items to be stored with the capability of accessing each

item by pointing to its location within the array.

0 1 2 3

0 A B C D

1 E F G H

2 I J K L

3 M N O P

The reason why this type of array is referred to as a

‘one-dimensional array’ is that it only uses a single

number to point to the position of array elements.

Two-dimensional arrays

Two-dimensional arrays are a little more complex than the one-

dimensional versions, but really they are nothing more than an array of

arrays, in other words an array in one row and another in the next row.

4 Q R S T

Hardware

Hardware is a name given to a collection of physical ‘things’ that when

put together in a certain way form a ‘system’.

Computer hardware: system unit

Within a computer system there are basically two types of hardware. The

hardware within the system consisting of the CPU (central processing

unit), which is situated on a printed circuit board called the motherboard.

There is the hard disk drive, the RAM (random access memory), optical

drive and other circuit boards such as the graphics and sound cards.

These are all regarded as hardware because if you removed the case you

could physically touch the devices – although you should not do this

unless you know what you are doing.

Describe what the purpose of CPU & RAM along with

typical specs and costs each.

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