Friday, January 15, 2016

One Step Equations involving Decimals

In this video you will learn how to solve one step equations that contain decimals.
In the I video I solve three types of problems involving decimals,addition,multiplication, and division.

The goal when solving one step equations is to isolate the variable by undoing operations, and whatever you perform on one side of the equation you must perform the same operation on the other side of the equation.

Whenever you add decimals together you need to line the decimals up in a straight line.
For example, 2.4 + 23.7
Line the decimals up,     23.7
                                      + 2.4

When multiplying decimals I find it helpful to follow these steps.

Step 1. Count how many numbers are to the right of the decimal.

Step 2. Multiply the numbers as if there are not any decimals.

Step 3. Take the solution from step two, and add the decimal back, making sure you have correct amount of numbers to the right.
An example will help

Multiply   2.5 x 2.15
Step 1. I have three numbers to the right of the decimal point.

2.5 has one, and 2.15 has two decimals to the right.

Step 2. 25 x 215 = 5375

Step 3 Count three places to the right and add the decimal  5.375

When dividing decimals you will need to get rid of the decimal of the the divisor.
and move the decimal the same amount of the divedend.

For example  124.2  ÷ 2.3

After removing the decimal of the divisor I have,   1242 ÷ 23 = 52
I moved the decimal one to the right with 2.3 in order to get rid of the decimal, therefore 124.2 becomes 1242 after moving the decimal one place to the right.

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