Cameron realizes that Ferris's plan to take off miles from the speedometer by pushing the pedal while in reverse isn't working. This clip can illustrate that distance cannot be a negative value.
To fool Hacker, the CyberSquad makes a robot that looks like Dr. Marbles. They notice that both sides of the Doctor are symmetrical, so they match up robot part halves that mirror each other.
The captain tells the squadron that he is expanding it to four members, which concerns all of the lieutenants. Lt. Purcell states that four is an unlucky number because it's not prime. He then defines a prime number.