Q&A for How to Do Lattice Multiplication

You have to add by how it's going diagonally. For example: for /0/3/ over /9/2/, 3 + 2 is 5 and 0 + 9 is 9. Your answer is 59.

You should never end up with 100, as you are multiplying single digits. 9 x 9 is the highest you will do, which is 81.

This method should work regardless of the sizes of the factors. Just be careful while adding up the long diagonals.

This method is designed for multiplying natural numbers and isn't well adapted for signed multiplication. Best approach here is to multiply the absolute values of the factors, then apply the appropriate sign to the product. The product of two positive factors, or two negative factors is positive; if one factor is positive and the other is negative, then their product is negative.

Because the bottom right triangle represents the position for the unit digit. The region above that between the diagonals represents the position for the tens digit, and so on.

First, draw a rectangle and draw 3 lines going vertically. Then, draw the diagonal lines (shown in step 3) write the 4 digit number you are multiplying with the 1 digit number on top of the table (step 2) and multiply, when you are done multiplying, add the numbers vertically. Finally, you have your answer.

If you are talking about carrying, simply put the units digit outside and keep the tens in your head, adding the tens to the next place.

This is a new and innovative method, and in many kids’ opinion: easy. The traditional method is good, but when it comes to long strings of numbers, it gets difficult and mistakes get easily made. If your child is confused, they don’t have to learn it. This is just a easier method of multiplication. The reason some schools may teach this is that it is a simpler method. You do not have to learn it to be successful in math.