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Simple Math ​

In the first lesson, we saw how we could print text using Python! Now, let us explore what else we can do. Read the line of code below.

py
print(9+10)

Before running this program, what do you think the program will output? Write your guess in the box below.

Copy the code into your Python editor and run it. Did the result match what you thought would happen?

Math Operations ​

Python can do math for us. Try it out yourself.

  • + this signifies addition. For example: 3 + 5
  • - this signifies subtraction. For example: 10 - 7
  • * this signifies multiplication. For example: 12 * 2
  • / this signifies division. For example: 15 / 3

Use Python to calculate the answer to each of the expressions above.

Order of Operations ​

Consider the expression below:

5 + 2 * 2

What do you think the answer is? Write your guess in the box below.

This is an example of ambiguity

DEFINITION

Ambiguity: Ambiguity is the condition where there may be more than one right answer. It may occur because we do not have enough information.

Why does the example above have ambiguity?

  • You first perform 5 + 2 to get 7, and then you multiply 7 * 2 to get 14. Your final answer is 14.
  • You first multiply 2 * 2 to get 4, and then you add 5 + 4 to get 9. Your final answer is 9.

In order to eliminate ambiguity, we use parentheses to say which math operation should be performed first.

5 + (2 * 2)

We first calculate the values inside the parentheses. This gives the expression below.

5 + 4

Now, we perform the addition to get 9. The parentheses told us what operation to do first. If we wanted to do the addition first, we would write this:

(5 + 2) * 2

Exercises ​

EXERCISE 1

Simplify the expression:

17*345+6543/3+77-2+89

Hint: You can use Python to help you.

EXERCISE 2

Calculate the value of the expression below

14+24+14+14+4

Recap ​

  1. Python can be used as a standard calculator to simplify math equations