This is a series of mathematics lessons that will review the important topics in arithmetics.
In these lessons, you will learn Approximation, Addition, Subtraction, and Multiplication of Decimals.
These lessons will also be useful as a pre-Algebra review.
The videos are presented by the Portland Community College.
Approximation of Decimals
Addition of Decimals
Subtraction of Decimals
Multiplication of Decimals
1) Multiply as if they were whole numbers (that is, disregard the decimal point)
2) Count the total number of decimal places in the factor (the multipliers)
3) Starting at the right end digit of the "answer", count off the same number of places
4) If more places are needed, insert additional zeros at the front.
Errata: (205.6)(0.312) = 64.1472
Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.