1. Python
Creating a calculator

2. Making a Calculator
How do you use a calculator?
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3. Making a Calculator Steps (Algorithm) Input the first number
Input the operator
Input the second number
Calculate the result (press the = key)
Display the result
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4. Making a Calculator Steps (Algorithm) Input the first number
Input the operator
Input the Second number
Calculate the result
Display the result
What happens to this data?
Is it necessary to input this?
What happens to this data?
Where does this go?
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How many pieces of data are there?
What datatype are they?

5. How a calculator works
The calculator uses some important concepts which are similar to programming
It has input (the numbers 9 and 4) – these are called variables
Variables are held in temporary storage
The calculator used an operator (/) divide.
The calculator used an assignment operator ( =).
In Python programming this does not mean equals
Equals is written (==)
a == 7, this means a has the same value as 7
a = 7, this means assign the value of 7 to a
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6. Activity 1 – Part 1
The calculator program will add up two numbers and then return the answer to the screen
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7. Activity 1 – Part 2
Extend your code so that it now multiplies, subtracts and divides the two numbers and displays the answer to each calculation on the screen at the same time. (use copy and paste to make this an easy task!)

8. Activity 1
Extension
Allow the user to input the two numbers to be used in the calculations (Hint you will need to convert the number to an integer – see here for more details
Allow the user to input which arithmetic operator they want to use
3. Allow the user to enter floating point numbers and display the result to 2 decimal places

9. Casting a Numeric Variable
Numbers typed into Python arrive as a string
They must be converted to a number before using in arithmetic
number1
“29” 29
number1
number1
“29”