CHAPTER 11: PERCENTAGES

11.1: Using Mental Methods

Ø  EXPLANATION:

·         Some percentages are easy to findà For Simple Fractions.

·         If you know 10%, you can find any multiple of 10%.

·         You can often do this quite easily. (Don’t always need a calculator)

Ø  EXAMPLE:

There are 4400 people in a stadium. 60% are males. How many is that?

ü  60% = 50% + 10%

ü  50% of 4400 = 2200

ü  10% of 4400 = 440

è 60% = 2200 + 440 = 2640

Work out:

ü  49% of 2300

ü  49% = 50% - 1%

ü  50% of 2300 = 1150

ü  1% of 2300 = 23

ü  49% = 1150 – 23 = 1127

ü  110% of 36

ü  110% = 100% + 10%

ü  100% of 36 = 36

ü  10% of 36 = 3.6

ü  110% = 36 + 3.6 = 39.6

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Show that 30% of 65 is the same as 65% of 30

 (30 : 100%) x 65 = 19.5

     (65 : 100%) x 30 = 19.5

Network Topology

Network topology is the arrangement of the various elements (links, nodes, etc.) of a computer network.Essentially, it is the topological structure of a network, and may be depicted physically or logically. Physical topology refers to the placement of the network's various components, including device location and cable installation, while logical topology shows how data flows within a network, regardless of its physical design. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ between two networks, yet their topologies may be identical.

A good example is a local area network (LAN): Any given node in the LAN has one or more physical links to other devices in the network; graphically mapping these links results in a geometric shape that can be used to describe the physical topology of the network. Conversely, mapping the data flow between the components determines the logical topology of the network.

Topologies remain an important part of network design theory. You can probably build a home or small business computer network without understanding the difference between a bus design and a star design, but becoming familiar with the standard topologies gives you a better understanding of important networking concepts like hubs, broadcasts, and routes.

In computer networking, topology refers to the layout of connected devices. This article introduces the standard topologies of networking.

Topology in Network Design

Think of a topology as a network's virtual shape or structure. This shape does not necessarily correspond to the actual physical layout of the devices on the network. For example, the computers on a home LAN may be arranged in a circle in a family room, but it would be highly unlikely to find a ring topology there.

Network topologies are categorized into the following basic types:

• bus
• ring
• star
• tree
• mesh

More complex networks can be built as hybrids of two or more of the above basic topologies.

Here are some explanations of the 2 types of Typology:

Tree Topology

Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the root of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.

Mesh Topology

Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing.

A mesh network in which every device connects to every other is called a full mesh. Partial mesh networks also exist in which some devices connect only indirectly to others.

Source: http://compnetworking.about.com/od/networkdesign/a/topologies.htm http://en.wikipedia.org/wiki/Network_topology 

Math Chapter 10.2

Using Statistics

In a real situation, you need to decide which one to use.

If you want to measure how spread out a set of measurements is, the range is the most useful statistic.

If you want to find a representative measurement, you need an average. Should it be the mode, the median, or the mean? That depends on the particular situation.

Here is a summary to help you decide which average to choose:

• Choose the mode if you want to know which is the most commonly occurring number.
• The median is the middle value, when the data values are put in order. Half the numbers are greater than the median and half of the numbers are less than the median.
• The mean depends on every value. If you change one number you change the mean. 

 Worked Example:

Here are the ages, in years, of the players in a football team.
Work out the average age. Give a reason for your choice of average.

16

17

18

18

19

20

20

21

21

32

41

Answer:

> The mode is not a good choice.
   --->   There are 3 modes. Each has a frequency of only 2.

> The mean will be affected by the two oldest people.
  ---> They are much older and will distort the value. In fact the mean is 22.1 and 9 people are younger than this; only 2 are older.

> The median is 20 and this is the best average to use in this case.
  ---> 5 players are younger than the median and 5 are older.

Math Chapter 10.1

Calculating Statistics

You can use statistics to summarise sets of data.
You can also use them to compare different sets of data.

You should already be able to calculate three different averages:

• the mode
• the median, and
• the mean.

Remember, that the range is not an average. It measures how spread out a set of values or numbers is.
For a large data, it is not practical to list every number separately. Instead,you can record the data in a frequency table.

• The mode is the most common value or number.
• The median  is the middle value, when they are listed in order.
• The mean is the sum of all the values divided by the number of values.
• The range is the largest value minus the smallest.

Example:

The table shows the number of beads on 200 necklaces.

Number of beads	25	30	35	40	45	50
Frequency	34	48	61	30	15	12

 
a. find the mode.
b. find the mean.
c. find the range.


Answer:

a. the mode is 35.               
 ---> the mode number is the number with the highest frequency.


b. 6900 : 200 = 34.5         
 ---> (25 x 34) + (30 x 48) + (35 x 61) + (40 x 30) + (45x15) + (50  x 12) : the sum of all the frequencies

c. 50 - 25 =  25                
 ---> This is difference between the largest and smallest number of beads.

                                                 

Computer and Mobile Network

Computer Network:

• its allows computer to exchange data
• passes data to each other along data connections
• the connections are established using either cable media or wireless media
• the best known computer network is known as the Internet
• designed for entry-level students to develop skills needed to gain employment as computer network installation, configuration, and support technicians

Network computer devices that originate, route and terminate the data are called network nodes.Nodes can include hosts such as servers and personal computers, as well as networking hardware. Two devices are said to be networked when a device is able to exchange information with another device.

Computer networks support applications such as access to the World Wide Web, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications. Computer networks differ in the physical media used to transmit their signals, the communications protocols to organize network traffic, the network's size, topology and organizational intent.

Mobile Network:

• can make and receive telephone calls over a radio link while moving around a wide geographic area
• by connecting a cellular network provided by a mobile phone operator
• as a convenient tool to stay in touch with people

In addition to telephony, modern mobile phones also support a wide variety of other services such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming and photography. Mobile phones that offer these and more general computing capabilities are referred to as smartphones.

This technology works by dividing the Earth into small regions called cells. Within each cell the wireless telephone signal goes over its assigned bandwidth to a cell tower, which relays the signal to a telephone switching network, connecting the user to the desired party. 

resources: http://en.wikipedia.org/wiki/Computer_network http://en.wikipedia.org/wiki/Mobile_phone https://www.rtc.edu/Programs/TrainingPrograms/CNT/ http://www.huffingtonpost.com/tag/cell-phone-technology http://dictionary.reference.com/browse/wireless

SOSE mind-map chapter 5

What Type of Teenager Are You?

1. If you were asked by someone to hang out, what would you answer:

a. directly say 'yes'
b. think first
c. directly say 'no'


2. If you were on holidays, what would you do:

a. Hang out with friends and family
b. Stay at home (with gadgets and stuff)
c. Sleep and be lazy

3. If you were bored in the class, what would you do:

a. Skip the class
b. Talk with friends / draw / do something else
c. Sleep

4. If your teacher gave you homeworks on holiday, what would you do with it:

a. Do it on last days of the holiday
b.  Not really care if you wouldn't do it or not
c. Do it directly so you wont be disturbed by homeworks on your holiday

5. If your mother asked you to buy something in the grocery store, what would you respond:

a. Give reasons so your mother would ask another person
b. Think first to say yes or no
c. Directly say 'yes'





Result:

• If your answers are mostly A, you are a type of teenager: easy going, have and enjoy your own world, friendly with people around you, independent, care about youself more than  people around you, sometimes can be selfish but actually nice, not really open to your family, like to pretend and hide what you feel, you talk more to your friends than family.
• If your answers are mostly B,  you are type of teenager: like to play with your gadgets, sometimes can be really lazy, like to play games when you're bored, not really friendly with people around you,  have your own world in gadget (socialize in social media), think logically.Not really open to other people.
• If your answers are mostly C, you are a type of teenager: you are lazy but sometime can be dilligent, do something you rarely do if you want something really bad, spend more time on sleeping, really enjoying your life, dont care about other people opinions on you, dont rush things, relax.

Note:

based on our experience (Tsamara and Indah)

-English-