1.0 X 21 = 21 or 210 because of the decimal point, I just don't remenber how the decimal point works.
Here's one way of looking at it.
If you buy something for $1.25, you know you are going to pay a one dollar bill and a 25-cent piece (a quarter). The decimal comes after the whole number.
So 1.0 is the same as 1.
1 * 21 = 21
To understand how the decimal point works in multiplication, let's break it down step by step.
First, let's focus on the whole numbers. In this case, we have 1 multiplied by 21. When multiplying whole numbers, you simply multiply the digits without considering the decimal point. So, 1 multiplied by 21 equals 21.
Now, let's consider the decimal point. In order to determine the placement of the decimal point in the result, you need to count the total number of decimal places in both of the multiplicands. In this case, 1.0 has one decimal place, and 21 has zero decimal places.
Since there is a total of one decimal place between the two multiplicands, the decimal point in the result should be placed one decimal place from the right.
So, the final result of 1.0 multiplied by 21 is 21.0 (or simply written as 21 without the trailing zero if the zero is not significant in your context).
To summarize, when multiplying decimals, multiply the whole numbers first, and then place the decimal point in the answer based on the total number of decimal places in the multiplicands.