See how long you can keep your ship's health above zero by using your skill of multiplying single digit numbers. Dodge enemy torpedoes while launching depth charges to destroy enemy subs. Set the depth charge depth to the product of the multiplication problem on a sub and let the depth charge fly.
Keyboard/Mouse: Click number keys or numbers on keyboard to enter depth. AD keys or arrow keys to move. Click X button or hit X key on keyboard to clear depth. Hit spacebar to launch depth charge or click the Launch button. Touch: use the on-screen buttons to enter depth, launch depth charge, and clear depth. Use arrow buttons to move. Click the video button on the main menu to see how to play.