math CHAPTER 11

CHAPTER 11 PERCENTAGES

·      11.1 à some percentages are easy to find because they are simple fractions. they are example of these on the first page of this unit, you can use the easy ones to work out more complicated percentages. You can often do this quite easily. You do not always need a calculator.

·      Example:

Ø there are 4600 people in a stadium. 58% are males. How many is that ?

100%=4600

58%= 50%+10%-2%--> these all the easy percentages to find.

50%=2300à 50%=1/2

10%=460à1/10 is easy. Just divide by 10

1%46àdivide 10% by 10 to find 1

58%= 2300+460-(2x46)= 2668 à do this sum in your head / on your paper.

Otherà you could have found 50%+5%+3%. Is that easier? J

Ø 90% of 320=?--> 320-3.2= 316.8

Ø show that 20% of 45 is the same as 45% of 20.

  So,   and     the result both of them are same.

·        11.2 à you will often need to compare groups that are different sizes. Suppose that, in one school, 85 students took an exam and 59 passed. In another school, 273 students took an exam and 147 passed. Which school did better? It’s hard to say because each school had a different number of students. The worked example shows how to use percentages to help to answer question like this.

·      Example:

Ø    In school A, 85 students took a mathematics exam and 59 passed.in school B 237 students took a mathematics exam and 147 passed. Which school had better pass rate?

59 out of 85 = 59 ÷ 85 = 69%  à  59 ÷ 85 = 0,694... =69% to the nearset whole number.

147 out of 237 = 147 ÷ 237 = 62%  à 147 ÷ 237 = 0,620.. =62%  to the nearset whole number.

The pass rate in school B is better by seven percentages points. à the difference between 62% and 69% is given on ‘percentages points.’

·       11.3 you can use percentages to describe a change in a quality. It could be an increase or a decrease. a percentages change is always calculated as apercentages f the initial value. The initial value is 100%. It is impothant to choose the correct value to be 100%

Topology of Network

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 topologyshows 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.

Diagram	Kind of Topology	Description, Advantages, and Disadvantages
	Ring	Description: Devices are connected from one to another to form a ring shape. Each host is connected to the next and the last node is connected to the first. A data token1 is used to grant permission for each computer to communicate. Advantages: Easy to install and wire. Because every computer is given equal access to the token, no one computer can monopolize the network. Disadvantages: Requires more cable than a bus topology. If one computer fails it can affect the whole network. It is difficult to identify the problem if the entire network shuts down.
	Bus	Description: All hosts are connected to the backbone cable in a linear2 fashion. Advantages: Easy to connect a computer or peripheral. Requires less cable length than a star topology. Disadvantages: If there is a break in the backbone cable, the entire network shuts down. Both ends of the backbone cable require terminators. It is difficult to identify the problem if the entire network shuts down.
	Star	Description: All hosts are connected to a single point of concentration. Usually uses a hub3 or switch4 as a center node. Range limits are about 100 meters from the hub Data on a star network passes through the hub or concentrator before continuing to its destination. Advantages: It is easy to modify and add new computers to a star network without disturbing the rest of the network. If one node or workstation (beside the middle node) goes down, the rest of the network will still be functional. The center of a star network is a good place to figure out where the network faults are located. You can use several cable types in the same network if the hub you have can handle multiple cable types. Disadvantages: Requires more cable than a bus topology. If the middle node goes down , then the entire network goes down. It is more expensive than because all cables must be connected to one central point.
	Mesh	Description: Each host is connected to all the other hosts. Advantages: Increased reliability since there are multiple paths for each node to take. Increased speed since shortcuts have been created by add more cables/links. Disadvantages: The cost of cabling all the hosts together is expensive and time consuming.

more deep explanation of some like up diagram :) 

Bus Topology

Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.Ethernet bus topologies are relatively easy to install and don't require much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.

Ring Topology

In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.

Star Topology

Many home networks use the star topology. A star network features a central connection point called a "hub node" that may be a network hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.
Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)



RESOURCES : http://www.sis.pitt.edu/~icucart/networking_basics/networking_topology.html , http://en.wikipedia.org/wiki/Network_topology , https://www.google.com/search?output=search&sclient=psy-ab&q=type+of+topology&btnK= , http://compnetworking.about.com/od/networkdesign/a/topologies.htm , http://whatis.techtarget.com/definition/network-topology

mobile technology and IT technology

Mobile technology is the technology used for cellular communication. Mobile code division multiple access (CDMA) technology has evolved rapidly over the past few years. Since the start of this millennium, a standard mobile device has gone from being no more than a simple two-way pager to being a mobile phone, GPS navigation device, an embedded web browser and instant messaging client, and a handheld game console. Many experts argue that the future of computer technology rests in mobile computing with wireless networking. Mobile computing by way of tablet computers are becoming more popular. Tablets are available on the 3G and 4G networks.Android 2.2 Froyo, 2.3 Gingerbread, and 4.0 Ice Cream Sandwich on the other hand, continue their decline. All three versions dropped their cut of the overall distribution. Gingerbread and Ice Cream Sandwich were the biggest losers with 2.9% and 1.7% drops respectively, which is actually more than they lost last month, hinging at updates intensifying.

Curiously, Android 3.2 Honeycomb is still refusing to disappear form the map. The tablet-only Android version continues to sit on a 0.1% share – it has been there for a few months now.A mobile phone (also known as a cellular phone, cell phone, and a hand phone) is a device that can make and receive telephone calls over aradio link while moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network. By contrast, a cordless telephone is used only within the short range of a single, private base station.

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.

Information technology (IT) is the application of computers and telecommunications equipment to store, retrieve, transmit and manipulate data,often in the context of a business or other enterprise The term is commonly used as a synonym for computers and computer networks, but it also encompasses other information distribution technologies such as television and telephones. Several industries are associated with information technology, such as computer hardware, software, electronics, semiconductors, internet, telecom equipment, e-commerce and computer services.Technology (from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία,  is the making, modification, usage, and knowledge of tools,machines, techniques, crafts, systems, and methods of organization, in order to solve a problem, improve a pre-existing solution to a problem, achieve a goal, handle an applied input/output relation or perform a specific function. It can also refer to the collection of such tools, including machinery, modifications, arrangements and procedures. Technologies significantly affect human as well as other animal species' ability to control and adapt to their natural environments. The term can either be applied generally or to specific areas: examples include construction technology, medical technology, and information technology.



resources:http://en.wikipedia.org/wiki/Mobile_technology, http://en.wikipedia.org/wiki/Information_technology, http://www.gsmarena.com/android_in_december_2013_kitkat_jelly_bean_on_the_rise-news-7540.php,http://en.wikipedia.org/wiki/Mobile_phone,http://en.wikipedia.org/wiki/Technology,http://www.nytimes.com/pages/technology/,http://www.infoworld.com/news

Math. retype chapter 10.1-10.2 (presenting data)

10.1 calculating statistics.

      you can use statistics to summarise sets of data. you can also use them them to compare different sets of       data. you should already be able to calculate three different averages: the median and the mean.
      remember that the range is not an average. it measures how spread out of set of value or number is.
      for a large set of data is not practical to list every number separately. instead, you can record the data in         frequency data.

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 values divide by the number of value.

The range is the largest value minus the smallest.

A frequency is any table that records how often (frequently data occur.

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

a. the mode is 35 à the mode is the number with the highest frequency

b. 6900÷200= 34.5 à (25 x 34 x 48 + 35 x 61 + 40 x 30 + 45 x  15 + 50 x  12 )÷ the sum of  all the frequencies. This is a reasonable answer because its near the middle of all the possible number of beads.

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

10.2 using statistics

    now you can work out several different statistical measures. in a real situation, you need to decide which       one to use. if you want to measure how spread out of a set of measurement is, the range is the most useful    statistics. if you want to find a representative measurement, you need an average. should it be the mode,        the median or mean? that depends on the particular situation. here is the 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 the numbers are less than the median.
• the mean depends on every value. if you change one number you change the mean

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 averages.
16,17,18,18,19,20,20,21,21,32,41.
the mode is not a  good choice. --> there are three modes. each has a frequency of only two
the mean will be affected by two oldest people. --> they are much older and will distort the value. in the fact the mean is 22.1 and nine people are younger than this; only two are older.
the median is 20 and this is the best average to use in this case. --> five players are younger than the median and five are older.

sose mind-map chapter 5

are you a vegetarian?-english-

1. if you saw a box of snack, would you?
    a. throw it away
    b. leave it
    c. take it away

2. if you saw a soup full of vegetable, would you?
    a. eat it
    b. eat the half of it
    c. throw it away

3. if you saw meat with vegetable which one would you take?
    a. vegetable
    b. both of it
    c. meat

4. imagine you have to eat meat and no vegetable, would you?
    a. no need to eat
    b. eat the half of it
    c. eat it

5. imagine your friend give you a box of food and meat, would you?
    a. say that you're a vegetarian
    b. take it but then throw it away
    c. take and eat it


answer:
if A you are trully deeply a vegetarian person. but sometimes you need to eat some meat to meet the needs of your body.:)
if B you are going to be a vegetarian.
if C you are not a vegetarian at all. but remember you need to eat vegetable to meet the needs of your body:)