I am remaking the ITPs so that they will work on all modern browsers and tablets. They will remain freely available to all without the need for a subscription.

This ITP allows you to set up a multiplication grid to demonstrate the grid method of multiplication for whole and decimal numbers. The grid size can be changed to accommodate different calculations. The calculation is defined at the bottom of the screen by changing the digits using the hidden pointers. Decimal points can be inserted by clicking between two adjacent digits. The numbers are partitioned and the respective components in the calculation revealed and hidden by clicking on the ? in the cell. These values appear in the addition calculation and the answer confirmed clicking on the equals sign below the plus sign. The numbers around the grid, and in the calculation, can be hidden and revealed. To do this, hover over and clicking on the rectangular strips, at the right hand side of, or below, each number.