Math Lesson 1 Instruction, page 1

Instruction 1-3

Read and Write Whole Numbers in the Millions | Order and Compare Whole Numbers and Decimals | Order of Operations Using a Scientific Calculator | Order of Operations: the Manual Approach | Round off Whole Numbers

Order of Operations Using a Scientific Calculator
CA GR6 AF 1.4

Even simple math problems can be confusing if a student does not understand how to get the answer. Should you multiply or

add numbers first? Do parentheses or exponents come first? The Order of Operations is a way to get to the bottom of these problems. The Order of Operations explains which steps to do and the order in which to do them. Modern scientific calculators will do all problems using the correct order of operations, as long as a student knows how to use the calculator correctly. Doing the problems without the benefit of a scientific calculator is trickier and we shall look at that after we study the calculator.

Using the Scientific Calculator

Example 1.

The answer you will get is 21.

Example 2.

To raise a number to a power, there are different buttons depending on the calculator. Some calculators have a or a button. Others have the “Hat”, or a button that looks like this . To correctly answer this problem using your scientific calculator, you would enter the following into your calculator:

No matter which key you use to enter the problem, the answer you will get is 3.

Example 4.

To multiply a number by parentheses, you need to include the × sign. This problem would be entered: . The answer you will get is 9.

Example 5.

When answering problems with multiple sets of parentheses, it is important that you write each set of parentheses. In this problem, you would enter the problem . You must enter both parts of both sets of parentheses. The correct answer you will get is 10.

Example 6.

This is a difficult problem because it involves all the tricks talked about earlier. To correctly enter this problem into your scientific calculator, you would have to enter it as follows:

No matter which key you use to enter the exponents, the correct answer you will get is 34.

Example 7.

This is a difficult question because you need to use the parentheses keys quite a bit, even though you don’t see any parentheses in the problem. To correctly answer this question, you need to type in the question putting parentheses around the operations on the top of the fraction problem and also around the operations on the bottom of the equation.

The problem reads: but should read .

To enter the problem correctly into the scientific calculator, use the following key strokes: . The answer to this question will be 1.

Problems with Fractions

Fractions follow the same Order of Operations as any other numbers. Different calculators have different buttons for dealing with fractions. The two most common are the or the UNIT and buttons.

Using the button. With this button, you enter it between each part of the fraction.

Example 8.

To complete this problem, enter the problem as follows:

On your calculator the answer will look like: which means .

Example 9.

To complete this problem, enter the problem as follows:

The answer you will get is which means .

Using the and keys.

Example 10.

To complete this problem, enter the problem as follows:

2 3 + 6 8 =

The answer you will get is which means .

Example 12.

The key is used to separate the whole number part from the fraction part of mixed numbers. The key is used to separate the parts of the fraction. So to complete this problem, enter the problem as follows:

7 1 7 - 4 5 6 =

The answer you will get is , which means .

Links for Students, Parents and Teachers

Now let's do Practice Exercise 1-3 (top).

Next Page: Order of Operations: the Manual Approach (top)