NumGam by SuperIlu is a puzzle game made for MS-DOS.
This game is more of called ‘a connect number’ game. Connect at least two adjacent fields with the same value by clicking and dragging. After that, you can add adjacent fields with either the same value or twice the value. The fields that are selected will be erased and the value of the last field will be updated. Deselect unwanted fields by backtracking. You can use the ‘Escape’ button to exit the game, but your progress will be lost.