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Understanding how to convert percentages to decimals is crucial when dealing with percent equations. To do this, you simply divide the percentage by 100. This action shifts the decimal point two places to the left. For example, to convert 240% to a decimal, divide 240 by 100, which equals 2.4.

Here's a helpful tip: You can also think of percentages as 'per one hundred'. So, 240% means 240 per 100, or simply 2.4 when you translate it into a 'per one' or decimal format. This is key when you're working with percentages in various mathematical problems, particularly in cases where you have to solve for an unknown variable.

When faced with a question that asks you for the 'whole' after being given the 'part' and the 'percent', you are essentially solving for the original number before the percentage was applied. This is often represented as 'W' in the percent equation formula. To isolate and solve for 'W', you'll want to divide the part by the decimal form of the percent.

To illustrate, let's use the exercise example. It states that 18 is 240% of what number? Converting 240% to a decimal gives us 2.4. Applying this to the equation, we get \( W = \frac{18}{2.4} \), which simplifies to \( W = 7.5 \). Thus, 18 is 240% of 7.5.

The percent equation formula is an essential tool for solving problems that involve percentages. It is expressed as \( P = r \times W \), where \( P \) is the part, \( r \) is the percent in decimal form, and \( W \) is the whole. This formula allows you to find any one of these three values when given the other two.

For instance, if a question asks you to find what part constitutes a certain percentage of a whole, you would multiply the whole (\( W \)) by the decimal form of the percent (\( r \)). Conversely, if you need to find what percentage a part is of a whole, you'd divide the part (\( P \)) by the whole (\( W \)) and then convert the decimal answer to a percentage by multiplying by 100. The simplicity and the versatility of the percent equation formula make it a powerful tool in mathematics, finance, and many real-life scenarios where percentage calculations are necessary.