Integration? Surplus? What?

Consumer Surplus, monetary gain obtained by consumers because they are able to purchase a product for a price that is less than the highest price that they would be willing to pay. To solve for consumer surplus, you have to integrate the Demand curve to the price at the market that is paid as shown in the diagram. Well, the hard part is to isolate the consumer surplus area it self. Economist will integrate a definite integral from 0 to q , where q is the quantity sold, and take away the rectangle area, which is called: total expenditure, P* x q*.

The problem will be, P=20 - 10^(0.1q). If the Price of the economy is $10, and the economy is selling at 10units. What will be the consumer surplus to the nearest integer.