Multiplying Three digit Numbers with Middle digit 2

1. Select a 3-digit number with a middle digit of 2.
2. Choose a multiplier with the same first two digits, whose third digit sums to 10 with the third digit of the first 3-digit number.
3. The last two digits will be the product of the third digits: _ _ _ _X X.
4. The third digit from the right will be 6: _ _ 6 _ _.
5. The next digit to the left will be 5 times the first digit of the number (keep carry): _ _ X _ _ _.
6. The first digits will be the square of the first digit plus the carry: X X _ _ _ _.

As you determine the digits in the answer from right to left, repeat them to yourself at each step until you have the whole answer.

Example:

1. If the first number is 622, choose 628 as the second number (same first digits, third digits add to 10).
2. 2 × 8 = 16 (multiply the third digits) - last two digits:
   _ _ _ _ 1 6.
3. The third digit from the right is 6:
   _ _ 6 _ _ _.
4. 5 × 6 = 30 (the next digit to the left is 5 times the first digit (keep carry 3):
   _ _ 0 _ _ _ .
5. 6 × 6 = 36; 64 + 3 = 39 ( the first digits are the square of the first digit plus the carry:
   3 9 _ _ _ _.
6. So 622 × 628 = 390616.