La cerise-sur-le-sundae-nateur - Monsieur

Otis and Olympia must join their friends at the party before it's over. They compare room temperatures to find the right one. Douglas Livraison needs help to calculate by leaps of five how many loaves of bread he needs to make his sandwiches.

Olympia makes divisions to add contestants to Orchid's talent contest. Olympia then uses a numerical ruler to find out which wrong-doer has given her a bad mark.

Olympia and Otis find a villain with the help of divisions. Otis teaches his colleagues how to round a number.

Oona uses coding to solve a problem with her identical robot. Otis divides food equally to please villains.

Debbie at Home helps secret agents stop a gang of vilains. They use a grid of 100. When Dr. O leaves OSI, Olympia uses her money to throw a party.

Otis and Olympia must find a way to cut expenses or the OSI office could close. Oona meets the new recruit replacing Dr. O and explains how a ruler works.

When the OSI goes bankrupt because of a group of adults, the agents are forced to become normal kids again.

OSI no longer exists. Mrs. O, Otis and Olympia notice that the number of unusual incidents increases according to the day of the week, using a bar graph. Mrs. O concludes that the OSI must return.

OSI agents save the planet from an invading creature.

Otis and Olympia investigate Negativille and learn about negative numbers. Oona learns to add from the sum total to pass her OSI exam.

Olympia and Otis have to determine a mathematical symbol used in an equation and do multiplications. Ocean learns to measure the circumference with a tape measure.

Mrs. O goes on a mission and the agents help each other to assist her from a distance. Otis and Olympia team up with a robot and find similarities between three locations.

Otis and Olympia must compete with other agents and use logical sequences to solve a problem. People in the city are moving in slow motion. Otis and Olympia investigate by comparing data.

The OSI and its enemies use programming to stop a dangerous giant robot. The agents misplace a guest at the OSI and must find the missing number in sums to find him.