Magnetic 100 Board. Kids will undo number gridlock and cruise from 1 to 100 with these foam magnetic number squares and 100 Grid Board. One side of the magnetic board features a 10" x 10" grid printed with numbers to 100. Flip it over and you have an empty grid ready to fill up with your foam magnetic numbers. Its handy size makes it perfect for individual deskwork. PLUS, the board features a write-on/wipe-off surface so you can use the blank grid with dry-erase markers for graphing and making charts.