Final answer:
To multiply a whole number by a fraction, we use division by the reciprocal of the fraction. Reciprocals are like numbers that help us reverse the division process. In time conversion, multiplying fractions by units of time, like 1/8 of an hour, gives us the result in minutes (7.5 minutes).
Step-by-step explanation:
When we multiply a whole number by a fraction as seen in your question, it often requires simplification. Taking the example provided, we multiply 2 by 1/15. To simplify this, we can remember that multiplication by a fraction is the same as dividing by its reciprocal. Therefore, multiplying by 1/15 is the same as dividing by 15. As a result, 2 multiplied by 1/15 equals 2/15 after simplification.
Moving onto reciprocals, if we have the reciprocal of 2.5, we would have 1/2.5. It's helpful to think of reciprocals as "like numbers," meaning that the essential feature of our reciprocal is the numbers that compose it when the decimal is ignored. Therefore, for 2.5, we start with a 4, resulting in a reciprocal of 4/10 or simplified to 2/5.
Applying these examples to time conversion, like finding out what 1/8 of an hour is in minutes, we multiply 1/8 by 60 minutes. Here multiplication is straightforward: 1/8 * 60 equals 7.5 or 7(1/2) minutes. This involves working with fractions and understanding the relationship between different units of measurement.