When multiplying numbers, the unit digit of the final product is determined by the product of the unit digits of the individual numbers.
For example, if we multiply 148 by 163 by 236, the unit digit of the final product will be the product of the unit digits of each of these numbers, which is 8 * 3 * 6 = 24.
Since 4 is the unit digit of 24, the unit digit of the final product will be 4.