Mental Math Basics: Place Values In Mental Math

Visit the link below for more information.

http://www.abellna.com

This video is about one of the basic principles used in mental math computations. Though simple to learn and apply, place values are essential to mastering mental math since they are used in many subjects but most important of all the digits are often referenced by their place values mentally. We probably learned of place values in the second or third grade or even in the first.

Every number has digits, and each digit resides in a different place value. Keep in mind a place value may sometimes be called a position.

Place Value = Position

Therefore, a place value defines the position of where a digit is in a number. For example, a number such as 1234 has four places values.

Starting right to left, the place values are as follows:

4: Ones
3: Tens
2: Hundreds
1: Thousands.

So where is the place value of the digit 2 is in 1234; it is in the hundreds place value and the hundreds place value holds a value of 100. The amount associated with the digit 2 in the hundreds place value is computed by multiplying the 100 of the hundreds place value by the value of the digit, 2 in this case.

100 X 2 -> 200

This means the digit 2 represents an amount of 200.

Here is how the amount of 1234 is computed based on the digit in 1234.

There are one 1000s, two hundreds, three tens, and four ones in 1234.

1000 + (2 * 100) + (3 * 10) + (4 * 1)

1000 + 200 + 30 + 4 -> 1234

The video focuses only on whole numbers but there is a brief over of decimal numbers. Whole numbers such as 4, 6, 123, 8373, and so forth do not have digits after the decimal point.

Decimal numbers have digits to the left and right of the decimal point.

123.67
549.09
2.3
67.89

Of course, there are many more place values on both sides of the decimal point; there are probably an unlimited number of them but only a few are used the majority of the time.

Place values are critical to mental math computations. Here, we use an example such as multiplying 141 by 6.

14 X 6 -> 84 -> 840
1 X 6 -> 6
84, 6 -> 846

840 + 6 -> 846

By understanding place values in mental math, the answer can be solved quickly in your head. Therefore, master mental math with place values.

Be sure to check back for other mental math basics or essential videos as they come online.

Check us at www.abellna.com.