It's always fun to learn new ways to multiply. Lattice multiplication was a method used a long time ago. Try it!|
1 Draw diagonals on graph paper or draw your own lattice.
2 Write one of the numbers to be multiplied above the lattice, each digit above a square.
3 Write the other number vertically, along the right-hand edge of the lattice, again placing each digit next to a square.
(See an example on the right, where we will be multiplying 378 times 43).
|4 Multiply the digits, placing the products within the grid.|
(In the top right box of our example, 8 times 4 equals 32, so we put the 3 above the diagonal and the 2 below the diagonal).
|5 Now, add the partial products from right to left, along the diagonals.|
(4=4, 2+2+1=5, and so on.)
6 Read the product down the left-hand edge and across the bottom of the lattice.
(The product is 16 254!)
7 Try another one!