Write a expression that can be used to multiply 6x198

In this problem, we are asked to give an expression that can be used to mentally multiply 6 and 198. In order not to go through the rigorous multiplication, we can estimate 198 to 200, that is 6 * 200 equal to 1200. Since there is a 2*6 excess or 12 then we subtract: 1200 - 12 equal to 1188.