Introduction to spreadsheets.

GOALS and Outcome

- Identify advantages and uses of spreadsheet software and charts/graphs.

- Identify and explain spreadsheet terminology.

- Create and save basic spreadsheets and apply formulas.

- Retrieve, edit, manipulate, and print various spreadsheets. 

- Create various charts/graphs from spreadsheets. 

What are Uses of Spreadsheets?

- Prepare budgets
      What is a budget?
      Why is it beneficial to have a budget?
- Maintain student grades
- Prepare financial statements
- Analyze numbers
      What is the definition of analyze? 
- Manage inventory
      What is inventory? 

- Make forecasts

Advantages of Spreadsheets

- Forecasting and making decisions
        Car Payment-Yes
        Rent-Yes
        House Payment-Yes
        Movies and eating out-NO

- Fast and efficient
- Spreadsheets Automatically recalculate with formula’s


Identify and explain spreadsheet terminology
 A spreadsheet tool used to play out different situations to determine the outcome
Student Discussion/Examples
What If……..Planning a Party
What If…….Shopping


Attributes of the Parts of the SS Window 
Active Cell
Cell is outlined in bold
Cell Address is in the upper left hand corner
 

Columns
Vertical portion of the spreadsheet
Identified by letters
 

Rows
Horizontal portion of the spreadsheet
Identified by numbers
 

Cell
Created by the intersection of a row and column


Entering Data into a Spreadsheet
 Labels
Alphabetical text

Values
A number

Formulas
Statement that performs a calculation

Functions
Built-in formula that is a shortcut for common calculations


Mathematical Operators
    +    addition
    -    subtraction
    *    multiplication    (asterisk)
    /    division    (slash or diagonal)    


Spreadsheet Functions 
Function Name             Description  
AVERAGE                     Average of arguments.
COUNT                          Counts the number of cells in a range.
IF                                    Specifies a logical test to perform; then                 

                                        performs one action if test result in true                

                                        and another if it is not true.
MAX                               Maximum value of range of cells.
MIN                                Minimum value of range of cells.
ROUND                          Rounds a number to a specified number of digits.
SUM                               Totals a range of cells.


Relative and Absolute Referencing 
Relative
cells that change when they are copied into other cells
 

Absolute
cells that do not change regardless of where it is copied
 
Graphing 
Bar graph
used to compare the values of various items

Line graph
useful for plotting trends

Area graph
like a “filled in” line graph.  Used to track changes over time

Pie graph
used to represent the percentage each item contributes to the total

Links to study for DUT exams

 JUST CLICK THE LINKS PROVIDED BELOW. THESE LINKS WILL SERVE AS YOUR NOTES.

 http://en.wikipedia.org/wiki/OpenOffice.org_Writer

http://wiki.services.openoffice.org/wiki/Documentation/OOo3_User_Guides/Writer_Guide/Introducing_Writer

http://www.linuxtopia.org/online_books/office_guides/openoffice_impress_guide/openoffice_impress_Parts_of_the_main_Impress_window.html

http://en.wikipedia.org/wiki/OpenOffice.org_Impress

Netiquette

Netiquette

View more presentations from andzoid.

Virus

Virus:
A computer virus is a computer program that can copy itself and infect a computer. The term "virus" is also commonly but erroneously used to refer to other types of malware.
Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer.

Malware:
Short for malicious software, is software designed to infiltrate a computer system without the owner's informed consent.
Malware includes computer viruses, worms, trojan horses, spyware, crimeware, most rootkits.

Worm:
is a self-replicating malware computer program. It uses a computer network to send copies of itself to other nodes (computers on the network) and it may do so without any user intervention. This is due to security shortcomings on the target computer. Unlike a virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.

Trojan Horse:
A Trojan horse, or Trojan, is malware that appears to perform a desirable function for the user prior to run or install but instead facilitates unauthorized access of the user's computer system. "It is a harmful piece of software that looks legitimate. Users are typically tricked into loading and executing it on their systems", as Cisco describes.
A Trojan horse may modify the user's computer to display advertisements in undesirable places, such as the desktop or in uncontrollable pop-ups, or it may be less notorious, such as installing a toolbar on to the user's Web browser without prior mentioning.
Once a Trojan horse has been installed on a target computer system, a hacker may have access to the computer remotely and perform various operations, limited by user privileges on the target computer system and the design of the Trojan horse

Spyware:
Spyware is a type of malware that is installed on computers and collects little bits of information at a time about users without their knowledge. The presence of spyware is typically hidden from the user, and can be difficult to detect. Typically, spyware is secretly installed on the user's personal computer. Sometimes, however, spywares such as keyloggers are installed by the owner of a shared, corporate, or public computer on purpose in order to secretly monitor other users.

Crimeware:
Crimeware is designed to perpetrate identity theft in order to access a computer user's online accounts at financial services companies and online retailers for the purpose of taking funds from those accounts or completing unauthorized transactions that enrich the thief controlling the crimeware.

Rootkit:
Rootkits can target the BIOS, hypervisor, boot loader, kernel or less commonly, libraries or applications.
The most common forms of rootkit either damage the systems they occupy or redirect the systems' resources for purposes ranging from pranks to gratifying their authors' egos to crime.

Virus vs. Worm:
A virus stays on your computer and your computer only.
Worms crawl through networks.
Unlike a worm, a virus cannot infect other computers without assistance. It is spread via trading programs with others (file sharing programs, email).

Spyware  vs. Adware:
Symptoms: Sluggish Pc, Increased pop-ups, homepage changes, strange search results.
Both are data miners, meaning they are looking for information. Both cause the above symptoms.
Can lead to identity theft.
9 out of 10 pc’s are infected.
Good place to look for info? http://www.webroot.com/spywareinformation

Spyware Removal:
You can try to do it manually- but is often very difficult. 
Often it can disrupt major computer processes.
You can check out the following free programs:
AdAware
SpySweeper (both versions, free&pay)
NOTE: Please be careful when downloading these tools, some programs claim to remove spyware, but instead, come with their own spyware embedded.

Top Spyware Threats:
PurityScan
N-Case
Gator
CoolWebSearch
Tansponder
ISTbar/AUpdate
KeenValue
Internet Optimizer (bargain buddy)
Perfect Keylogger
TIBS Dialer

For more information on these, visit:
http://www.webroot.com/spywareinformation/spywaretopthreats/

Basic Computer Maintenance

LCD Monitor:
- Do not touch or attach items to the screen.
- Turn off to clean.
- Spray mild window cleaner on a soft cloth.
- Do not spray directly on screen.
- Do not use paper towels.

Wires:
- Avoid pulling or putting stress on your wires.
- Avoid putting objects on top of wires.
- Always disconnect cords by grasping the plug, not the cord.

CPU:
-Turn power off before cleaning.
- Any type of household cleaner for outside.
- Once a month take off cover and gently blow off dust.
- Always disconnect power cord by grasping plug- not cord.

Surge Protectors:
- Use a surge protector to protect electronic devices from power surges.
- Will not offer 100% protection.
- To be safe, never use computer during a storm.

CD-ROM Drives:
- Always use the button to open and close the drive.
- Do not use compressed air to clean the floppy diskette, CD, DVD or Zip drives.

CDs and DVDs:
- Use a soft cotton cloth
- Wipe against the tracks starting from the middle and wiping outwards
- Never wipe with the tracks
- Water w/ soap or rubbing alcohol

Keyboard:
- Do not eat or drink while typing on your computer.
- Turn off before cleaning.
- Spray Windex onto cloth, not on keyboard
- Use Compressed air

Mouse:
- Clean the top of your mouse like your keyboard
- Scrape guck off bottom with your fingernail

Installing Software:
- Do not use “bootleg” software
- Be sure to reboot after each program is installed
- Test your computer for problems before installing another program

Protect Against Viruses:
- Don’t open email attachments from people you don’t know.
- If your computer suddenly starts acting strange, you should run a virus scan.
- Be careful about disks and CDs from other computers- not everyone has virus protection.
- Use a firewall. A firewall is a piece of software or hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the internet.
- Be careful about what you download from the Internet!
- Be sure that everyone who uses your computer follows these rules!

General Troubleshooting:
- If your computer does not start the first thing to check is the power source… is it plugged in?
- If your computer locks up (freezes) the first thing you should do is restart the computer.
- If your document fails to print you should check the
    a. paper supply,
    b. power source,
    c. paper feeder.
- If you install a new software program on your computer and it does not work the most likely reason is that you do not have enough memory.

Networking: Basic Topologies

Network Topologies

What is a Topology?
- The way in which the connections are made among all the computers is called the topology of the network.
- Network topology specifically refers to the physical layout of the network, specially the location of the computers and how the cable is run between them.

The most common topologies are:
Bus
Star
Ring 
Mesh

Bus:
The bus topology is the simplest and most common.
It is often used when a network installation is small, simple, or temporary.
It is a Passive topology. This means that computers on the bus only listen for data being sent, they are not responsible for moving the data from one computer to the next.

- In an active topology network, the computers regenerate signals and are responsible for moving the data through the network.
- On a  bus network, all the computer are connected to a single cable.
- When one computer sends a signal using the cable, all the computers on the network receive the information, but only one (Addressee) accepts it. The rest disregard the message.

Advantages of Bus:
1. The bus is simple, reliable in very small network, and easy to use.
2. The bus requires the least amount of cable to connect the computers together and is therefore less expensive than other cabling arrangements.
3. Failure of one node does not affect the rest of network.

Disadvantages of Bus:
1. Heavy network traffic can slow a bus considerably.
2. A break in the cable or lake of proper termination can bring the network down.
3. It is difficult to troubleshoot a bus.

Appropriateness of the bus topology:
- The network is small
- The network will not be frequently reconfigured
- The least expensive solution is required
- The network is not expected to grow much

Star Topology:
- In a star topology, each device has a dedicated point to point link only to central controller, usually called a hub/server/host.
- Each computer on a star network communicates with a central hub that resends the message appropriate computer(s)
- The hub can be active or passive.
- An active hub regenerate the electrical signal and sends it to all the computers connected to it.

Advantages of Star Topology:
1. It is easy to modify and add new computers to a star network
2. During adding/deleting a node network can function normally.
3. When the capacity of the central hub is exceeded, it can be replaced with one that has a larger number of ports to plug lines into.
4. Provide for centralised monitoring and management of the network.
5. Single computer failure do not necessarily bring down the whole star network.    

Disadvantages of Star Topology:
1. If the central hub fails, the whole network fails to operate.
2. It cost more to cable a star network.
3. Require dedicated server and NOS

Appropriateness of Star Topology:
- It must be easy to add or remove client computer.
- It must be easy to troubleshoot.
- The network is large.
- The network is expected to grow in the future.

Ring Topology:
- In a ring topology, each computer is connected directly to the next computer in line, forming a circle of cable.
- It uses token to pass the information from one computer to another.
- Every computer is connected to the next compute in the ring, and each retransmit what it receives from the previous computer.
- The message flow around the ring in one direction.
- Ring is an active topology.
- There is no termination because there is no end to the ring

Token Passing method:
Token passing a method of sending data in a ring topology
A small packet, called the token passed around the ring to each computer in tern
If a computer has information to send, it modifies the token, adds address information and the data and sends it down the ring.
The information travels around the ring until it either reaches its destination or returns to the sender.
A token can circle a ring 200 meters in diameter at about 10,000 times a second.

Advantages of Ring Topology:
1. All the computers have equal access to the network.
2. Even with many users, network performance is even
3. Allows error checking, and acknowledgement.

Disadvantages of Ring Topology:
1. Failure of one computer can affect the whole network.
2. It is difficult to troubleshoot the ring network.
3. Adding or removing computers disturbs the network.

Appropriateness of Ring Topology:
- The network must operate reasonably under a heavy load
- A higher-speed network is required.
- The network will not be frequently reconfigured.

Mesh Topology:
- In a mesh topology, every devices has a dedicated point to point  link to every other device.
- A fully connected mesh network therefore has n(n-1)/2 physical channels to link n devices.
- To accommodate that many links, every device on the network must have n-1 input/output ports.

Advantages of Mesh Topology:
1. Because of the dedicated link, no traffic between computers.
2. Failure of one node computer not affect rest of the network.
3. Because of the dedicated link privacy and security are guaranteed
4. Point to point links make fault identification and fault isolation easy.

Disadvantages of Mesh Topology:
1. Due to the amount of cabling and number of input output ports, it is expensive.
2. Large space is require to run the cables.

Variations of the Major Topologies:
1. Hybrid Star:
A star network can be extended by placing another star hub where a computer might otherwise go, allowing several more computers or hubs to be connected to that hub.

2. Star Bus:
The star bus topology combine the bus and the star, linking several star hubs together with bus trunks. If one computer fails, the hub can detect the fault and isolate the computer.
If a hub fails, computers connected to it will not be able to communicate, and the bus network will be broken into two segments that can not reach each other.

3. Hybrid Topologies:
Often a network combines several topologies as subnetworks linked together is a large topology.
For instance one department of business may have decided to use a bus topology while another department has a ring.
The two can be connected to each other a central controller in a star topology
When two or more topologies are connected together it forms a hybrid topology

Nature and Types of Software

Software - is the collection of computer programs and related data that provide the instructions telling a computer what to do.

There are two types of software:
1. Systems software: the operating system.
2. Applications software: the programs we use.

Systems software:
is the control software that operates the hardware and allows the applications to run.

Operating Systems:
- Operating Systems run in the background without the users being aware of it.
- It controls the inputs, outputs, interrupts, and storage of files as requested by the applications software.

- examples is the windows XP operating System

Efficient Management of the Computer Resources:
1. Managing memory, i.e. allocating memory to more than one program running simultaneously. Some files may get moved to the hard drive temporarily. The place on the hard drive is stored in a directory for fast access when needed again.
2.Interrupts, for Enter, Printer out of paper, or a hardware or software malfunction.
3.Diagnostic checks on the system on Boot up, sending error messages where necessary.
4.Selecting and controlling peripheral devices through small Driver programs.

Utility Programs:
Systems software include other utility programs such as:
1. Systems software include other utility programs.
2. Virus checking and cleaning.
3. Security using identification and passwords.
4. File and hard disk management for efficiency and storage.
5. Customising the computer to the users requirements, i.e. short cut menus from mouse click.
6. Setting peripheral devices to the users requirements, i.e. setting the monitor resolution.

Types of Operating Systems:
1. Command driven: DOS.
- the user has to type in the command
- it has to be in the correct syntax, errors were common
- more adaptable than Windows when used by an experienced user.

2. Windows, Icons, Mouse and Pull down menus.
- originally developed by Apple for the Macintosh
- later developed by Microsoft for Windows 3.1.
- uses a mouse to click onto an icon to navigate to programs and files.

Applications Software:
Used for a specific purpose or application:
- Word processing;
- Numerical analysis and storage;
- Recording of data;
- Designing and graphics;
- Image processing;
- Presentations;
- Desk top publishing;
- Web design.

Three Groups of application Software:
1. Generic:
- general purpose for business;
- most common applications are Word Processing, Spreadsheet & Database.
- Most generic software for business comes in an integrated package such as: Microsoft Office, Lotus Smart-Suite, Coral Draw.
- The cost of the integrated package is much less than the sum of the separate applications.
- Microsoft Office is the most popular package used in business, it contains the applications: Word, Excel, Access, Power-Point, Front-Page.

2. Bespoke:
- tailor made, specifically written for a specific application.
- Software that is specially written for an application.
- An expensive but a perfect solution to a requirement when there is no suitable package available.
- Often a one off piece of software written for a large organisation as a perfect match to their needs.

3. Specific Task:
particular tasks for business;
most common are payroll, CAD, and stock control.

Appropriate Software Packages:
1. In business the software needs are most important and the hardware is purchased to accommodate the applications.
2. If the hardware is already in place, the software has to be able to run on it.
3. Is the cost within budget?
4. Should it be evaluated for appropriate use?
5. What problems did other users have?
6. Does it contain any known bugs?
7. Is it easy to install and get up and running?
8. What technical support comes with it, is any training available, is there good documentation?
9. What are the details of the licence agreement?