Using Lattice Multiplication Post#3 Math 1510

        Lattice multiplication is a way of doing multiplication using a grid that looks similar to a lattice. It has been around for centuries and was first introduced in Europe in the early 1200's by Fibonacci. With practice this method can be quick and efficient in solving multiplication problems. When I first saw this method my daughter was in fourth grade and I wondered what in the world it was. I never took the time to find out so this chapter has really helped me to understand this method.
        Primary grade students have difficulty keeping the math columns aligned when they start to learn multiplication.  Lattice multiplication can help students who are struggling with this problem achieve success. By demonstrating the technique and process of this new math skill the students will be able to separate the multiplication from the addition in first filling in the lattice and then adding the contents. Some of the important points in this method are that it can be easily learned, keeps their work organized, and is diagnostic in that if they do get a wrong answer the student  can easily see where the mistake was made. This method breaks down the process into smaller steps which can help some students grasp the concept of multiplication easier because it is so visual. Here is how you use this method:

1. If you are multiplying two digits by two digits, you need a grid two squares across and two squares down. A three digit by two digit problem takes a two by three grid.

2. Divide each box diagonally from the upper right corner to the lower left corner. Start at the top left corner and write one of the numbers you are multiplying across the top edge of the grid ( around the outer edge, not inside the boxes), one digit per space. Write the second number down the right edge in the same manner.

3. In each box multiply the number at the top of the column with the number at the right of the row. Write the result in the corresponding box with the ones below the diagonal and the tens above the diagonal (if it is a single digit number, write "0" for the tens).

4. Add the numbers along each diagonal row from right to left and record the sums along the lower or left outer each. Carry the tens to the next diagonal when the sum is 10 or greater. Read your answer around the outer edge from top left to lower right.
        The only time consuming part of the lattice method is making the grid. The more activities the students do, the more proficient they will become at using this method in multiplying large numbers.

Lattice Multiplication