To convert 20 inches to centimeters, we will use the conversion factor of 1 inch = 2.54 centimeters. This means that for every 1 inch, there are 2.54 centimeters.
Step 1: Write down the given value of 20 inches.
20 inches
Step 2: Set up a conversion factor using the given ratio of 1 inch = 2.54 centimeters.
1 inch / 2.54 centimeters
Step 3: Now, write the given value of 20 inches as a fraction with 1 inch as the numerator.
20 inches / 1 inch
Step 4: In order to cancel out the inches unit, we will multiply the given value by the conversion factor fraction. This will give us our final answer in centimeters.
20 inches / 1 inch x 1 inch / 2.54 centimeters
Step 5: Simplify the fractions, and we are left with the value of 20 inches in centimeters.
20 / 2.54 centimeters
Step 6: Perform the multiplication (20 x 1) and (1 x 2.54) to get the final answer.
20 / 2.54 = 7.874015748 centimeters
Step 7: Round off the answer to the appropriate number of significant figures. In this case, since 20 inches only has two significant figures, the final answer will also have two significant figures.
Therefore, 20 inches is equal to 7.9 centimeters.
In conclusion, to convert 20 inches to centimeters, we first set up a conversion factor using the given ratio of 1 inch = 2.54 centimeters. Then, we multiplied the given value by this conversion factor to cancel out the inches unit and obtain the final answer in centimeters. Remember to round off the answer to the appropriate number of significant figures.