To calculate a percentage, divide the part by the whole and multiply by 100. For example, if you want to find the percentage of 25 out of 50, you would divide 25 by 50 (25/50) and multiply by 100 to get 50%.
To express a percentage as a decimal, simply move the decimal point two places to the left. For example, 50% would be expressed as 0.50.
To convert a decimal to a percentage, move the decimal point two places to the right and add the percent symbol. For example, 0.50 would be converted to 50%.
To show a percentage increase or decrease, you would first calculate the difference between the old and new values. Then, divide that difference by the old value and multiply by 100. If the result is positive, it is a percentage increase. If the result is negative, it is a percentage decrease.
To properly format a percentage, use the percent symbol (%) after the number. You can also include a space between the number and the percent symbol for clarity. For example, 50% or 50 % would both be acceptable ways to format a percentage.