PercentageCalculator .proWhat is 40 percent of 128?
Percentage Calculator
Visualizing Through Pie Charts
One way of visualizing 40 percent is through a pie chart. In this example, the orange slice represents the percentage of the whole pie.
40 percent pie chart
Visualizing Percentage with Bar Charts
Another way of visualizing percentages is using a bar chart like the one below. The orange bar represents 40, percent and the full square represents the whole or 100%.
40 percent bar chart
Solution for 'What is 40% of 128?'
In the following example, consider that:
- The percentage figure is represented by X%
- The whole amount is represented by W
- The portion amount or part is represented by P
Solution Steps
The following question is of the type "How much X percent of W", where W is the whole amount and X is the percentage figure or rate".
Let's say that you need to find 40 percent of 128. What are the steps?
Step 1: First determine the value of the whole amount. We assume that the whole amount is 128.
Step 2: Determine the percentage, which is 40.
Step 3: Convert the percentage 40% to its decimal form by dividing 40 by 100 to get the decimal number 0.4:
40100 = 0.4
Notice that dividing by 100 is the same as moving the decimal point two places to the left.
40.0 → 4.00 → 0.40
Step 4: Finally, find the portion by multiplying the decimal form found in the previous step by the whole amount:
0.4 x 128 = 51.2 (answer).
The steps above are expressed by the formula:
P = W × X%100
This formula says that:
"To find the portion or the part from the whole amount, multiply the whole by the percentage, then divide the result by 100".
The symbol % means the percentage expressed in a fraction or multiple of one hundred.
Replacing these values in the formula, we get:
P = 128 × 40100 = 128 × 0.4 = 51.2 (answer)
Therefore, the answer is 51.2 is that 40 percent of 128.