According to the basic properties of division operation, we can know that the dividend and divisor are expanded or reduced by the same multiple at the same time, and the result remains unchanged, so 22.59÷6.6=225.9÷66. The process of vertical division:

1. Divide by the high order of the dividend. How many digits is the divisor? Just look at the first few figures of dividends.

2. Calculate the largest quotient, except where the dividend is, where the quotient is written.

3. Then subtract the product from the current dividend, and the remainder of each division should be less than the divisor. When it is not enough, you need to borrow one from the previous one to count ten.