Week 2- Data, Sources And Usage(Grade 6)

Week 2- Data, Sources And Usage(Grade 6)

by Primus School

​A recap on the previous lesson W

​We lent of some types of data and what their characteristics are.

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​Do you remember what a 'boolean' data type is in computer science?

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​And what of 'Integer' ?

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​Can you remember the rules for integers?

​Rules for integers

• ​An integer must have at least one digit.

• ​An integer must NOT have a decimal point.

• ​An integer can be either positive or negative

​NULL

​Null data types identifies variables being empty or not and useful to differentiate between the empty string and null values of databases.

FLOATING POINT NUMBERS

​Floating point data types are used to represent numbers with a fractional part.

​A float (floating point number) is a number with a decimal point or a number in exponential / fractional form.

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​A real number with a decimal part used to perform calculations is a float.

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​Example = 10.365

DOUBLE DATA TYPE

​A double type can represent fractional as well as whole values. It can contain up to 15 digits in total, including those before and after the decimal point.

​ALPHANUMERIC STRINGS

​One of the most widely used data types is a string. A string

consists of one or more characters, which can include letters, numbers, and other types of characters. You can think of a string as plain text.

​A string represents alphanumeric data. This means that a string can contain many different characters, but they are all considered as if they were text, even if the characters are numbers. For example, the following code is used to print text to the screen:

Print 'Hello World!"

​The use of quotes ensures that the text 'Hello World!' is recognized as a string and not as two separate words that may have some special meaning in the programming language. The use of quotes also makes it possible to use numeric characters as part of a string. For example, the following code is used to store a street address:

Address '123 Central Avenue'

Without the quotes, the numeric characters 123 would be interpreted as a number, but with the quotes, it is recognized as being part of a string that represents a street address.

​CHAR DATA TYPES

​The abbreviation char is used as a reserved keyword in some programming languages, such as C, C++, C#, and Java. It is short for character, which is a data type that holds one character (letter, number, etc.) of data. For example, the value of a char variable could be any one-character value, such as 'A', '4', or '#'.

Character data type store strings of letters, numbers, and symbols. Data types CHARACTER (CHAR) and CHARACTER VARYING (VARCHAR) are collectively referred to as character string types, and the values of character string types are known as character strings.

Poll

How will you rate your understanding on what you have learnt so far?

• Excellent

• Very Good

• Good

• Bad

​Read through the text below and answer the questions that follow.

1. Mr. Thompson Gogovi, popularly known in his area as Mr. TG33 went to the "A" Supermarket in Anlo to buy a weighing scale and some other things. He paid for the scale and weighed himself only to realize that he had reduced weight to 142.8kg.

2. The shop owner asked him to fill a form to enable Mr. Gogovi enter into a draw the shop was organizing. Upon opening the form he saw only one question in it: "The first President of Ghana was Kwame Nkrumah a. False b. True.

He ticked the correct answer and paid for items he bought at a cost of 350 cedis cash. He was then given a raffle receipt with pin code -234000.

3. Two days later, Mr Gogovi was called that he has won biscuits, toffees and other packages in the raffle. He went and brought the items home dividing it into the fraction 2/4 among his kids.

Multiple Choice

The name ''A'' is what type of data?

• Boolean 

• Null

• Char

• Floating point 

Multiple Choice

What type of data is ''TG33"

• Alphanumeric

• Floating Point

• Integer

• Double

Multiple Choice

What data type is the weight 142.8 ?

• Integer

• Floating point 

• Char 

• Null

Multiple Choice

What data type is True/False ?

• Null

• Char

• Integer

• Boolean

Multiple Choice

What data type is  $$\frac{2}{4}$$  ?

• Floating point

• Integer 

• Char

• Boolean

​Random Answering Exercise.

​Exercise 8 and 9

​Pages 100-101

Poll

Rate your mood.

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​Well Done