# 4.2.3 Further Practice with PEMDAS

Scientific and graphing calculators will follow the PEMDAS code, and the calculator used in this course certainly does. However, be careful, because a typical handheld calculator might not be programmed to perform operations in the correct order, as described earlier in the pizza example.

The calculator can be accessed in the left-hand side bar under Toolkit.

## Activity: PEMDAS on Paper Versus the Calculator

To make sure that you understand PEMDAS, try these calculations in your math notebook without using the calculator. Then, check your answer using the calculator.

(a)

### Comment

Remember PEMDAS. Are there parentheses? Then do the calculation inside those first. Next, look for exponents, then multiplication, division, addition, and subtraction.

(a)

Carry out the calculation in parentheses first: . Now multiply by two and the answer is 14.

(b)

(b)

No parentheses, this time, so start with the exponent: . Add the two and you get 11.

(c)

(c)

This looks like part (b), but this time there are parentheses, so you must do the calculation inside the parentheses first: . Now square the result, and the answer is 25.

(d)

(d)

Work out the exponents first.  and . Finally add: .

(e) . Take care with this one!

It can help to make calculations like this easier to read if you put parentheses around the part that you need to do first.

(e)

This time, you have addition and multiplication, so you must do the multiplication first: . So now, the calculation is .

Using parentheses we would write .

This will give you the same answer but just might make your job easier!

Did you get the same answers using the calculator? You should!

4.2.2 Calculator Exploration: Understanding the Order of Operations

4.2.4 Moving Left to Right