[Lewis] has just the thing for that: a big expandable 7-segment display. The build is modular, allowing it to be extended from 2 to 10 digits ... can be built using an Arduino Nano or an ESP8266 ...

The matrix has seven columns, one for each segment on the display. Then there are ten rows, one for each digit from 0 to 9. The number 1, for example, needs only two segments to light up ...