The satisfaction or utility can be measured into numbers. For example, if a consumer drinks a glass of milk, the satisfaction he derives from that glass of milk can be represented into numbers like 1, 2, 4, 5, 15, 20 etc. In mathematics such number are called cardinal numbers. Accordingly, the utility approach is also given the name of cardinal measurement of utility. Thus, it is the view of ancient economists that the satisfaction or utility is a cardinally measurable quantity as length, weight and volume. Therefore, they accepted the existence of unit of measurement of utility called util.
Utility depends upon the units of one goods which a consumer is consuming in other words; according to classical economists utilities are independently determined. As you = f (Q), where you stands for utility, while Q represents the units of the particular goods which a consumer is consuming.
The behavior of all the consumers remains alike. This means that what is the behavior of a representative consumer, the same is the behavior of rest of consumers during the consumption.Consumer is rational, he is well aware of with his income and prices of goods in the market. The money is a measure which is employed to measure the utility of the goods and services and there is no exchange in marginal utility of money. It means that marginal utility of the goods may change while the marginal utility of money remains the same.