How does the grid work?
Blue cells at the top are your problem (the multiplicand and multiplier).
Yellow cells are where you write your carry-overs (the small numbers above the column).
White cells are where you write your partial products.
Green cells at the bottom hold the final answer.
Grey cells are blocked — no digit ever goes there. They just keep your columns lined up.
For each × row, multiply one digit at a time: write the ones digit in the white box, and if the result has a tens digit, write it in the yellow carry box above the next column. For the last step of each row, the tens digit goes in the next white box to the left instead of a yellow carry box.
When you add the columns at the bottom, include every digit in that column — the white pp digits and the yellow carries above them, plus any addition carry from the column to the right.
Start with the ones column on the right, then work left. Press Check my work to see how you did, or Hint to fill the next step.
Allow zeros only affects New random problems. When off, every digit of the random number is 1–9. When on, random numbers can include zeros in the middle (like 305 or 2070), which adds tougher cases like "multiply by 0" and "carry through a zero." It does not change anything you type yourself in Your problem from your book.