On seeing the place value of unit digits, we first multiply the unit digits.
If there is a carry over, we add it with the product of unit digit of the first number with the tenth digit of the second number. We accomplish this task by seeing the place values at the respective digits.
Then, we multiply the tenth digit of the first number with the unit digit of the second number by seeing their place values and repeat the process we did before.
By this way, place values are useful for multiplying two digit numbers.
