These problems multiple or divide numbers up to 12x12 timetables. The spreadsheets randomly generate problems every time you click on the title cell and press enter. Each sheet is unique due to the random algorithm used in the calculation, which I find reassuring as students memorize answers when reusing a math sheet multiple times. The sheets are provided in 10, 25, and 50 problems per page to provide the teacher support for the various levels of student capabilities