Use the lattice method to multiply.
987 × 8,246

Question

Quizplus · Accepted Answer

The lattice method involves creating a grid and placing the digits of each number along one of the edges, then multiplying to find the products and writing them in the appropriate boxes. Finally, diagonals are added to find the solution.

Here's what the lattice grid would look like for this multiplication problem:

| 9 | 8 | 7 |
    +-----+---+---+---|
    |     |   |   | 2 |
    |     |   | 4 | 4 |
    |     | 8 | 2 | 6 |
    +-----+---+---+---|

To fill in the boxes, you multiply the digits on each diagonal and place the product in the box:

| 9 | 8 | 7 |
    +-----+---+---+---|
    |     | 7 | 6 | 2 |
    |     | 8 | 1 | 2 |
    |     | 7 | 8 | 6 |
    +-----+---+---+---|

Then, you add up the diagonals to get the final answer:

8   0   7   1   7   8
    ×       9   8   7   0   0
    -----------------------
      7   7   4   8   9   6
    7   8   1   2   0   0
    6   2   4   4   0   0
    -----------------------
    8,123,602 Using the lattice method:
   9   8   7
   ---------
8|72|56|28|
2|16|28|46|
4|36|42|98|
6|54|35|03|
Add the diagonals and carry over as needed:
   9   8   7
   ---------
8|72|56|28|
2|16|28|46|
4|36|42|98|
6|54|35|03|
 + |57|29|5
   ---------
   8|14|23|2
   ---------
Therefore, the answer is 8,146,404.

Use the Lattice Method to Multiply