Multiplication puzzle paramétrable

‎www.taw.org.uk/lic/itp/mult_facts.html This ITP allows you to represent multiplication as repeated addition using a grid of blocks or counters. The grid can also be hidden. You first select the number of rows and columns in the grid. A similar representation appears on the screen when moving along the rows. In the example below with 5 rows and 9 columns, when you select to count along the columns the given calculation is: 5 x 9 = 45 [the 5 is multiplied by 9]. The ITP can be used to develop children's understanding of multiplication and to develop links between the different representations and notation.