"One + One = Ed" is the 4th episode of Season 2 and the 30th episode of Ed, Edd n Eddy. In this episode, the Eds embark on a learning spree, disassembling various objects and eventually stumbling into a bizarre universe that defies the laws of physics.
Eddy is shown happily asleep at night but wakes up to see Ed lying next to him in bed, asking how his feet can smell without a nose. Eddy yells at him to go home, but Ed asks a number of other useless questions to Eddy and eventually taking Eddy with him to the kitchen. While Eddy tries to get some sleep, Ed stays up all night opening and closing the fridge to figure out if the little light in the refrigerator stays on if the fridge is closed. In the morning, Eddy appears very sleep deprived. After failing to convince Ed to think of more useful questions, they visit Edd at his house and find him disassembling an old radio. Eddy then has an idea to get rich by learning and taking things apart.
They leave Edd's house and go to Ed's garage where they find a mountain of items. Ed takes apart a washing machine that he dumped on Eddy, finding one Eddy and a whole bunch of "doohickies" inside. After going though some other items in the garage, they decide to go somewhere else to learn more. They go to Rolf's house and disassemble a chicken pen. While Rolf tells them a story from his homeland, Ed takes hold of a tree and turns it, making it flat. Edd and Eddy examine the tree before leaving Rolf's house as its owner shouts that life has many doors.
It doesn't take long for Eddy to find his way behind the silhouetted houses in the backdrop. While Edd rambles about what's happening, Ed slides under the asphalt (which adapts fabric-like qualities), and Eddy crushes a house by jumping onto it. Eddy wants to take a break since the learning is making him hungry, but then he sees his hand go through the sun. He proceeds to eat the sun, causing it to become the moon and the cul-de-sac to become shrouded in nighttime. The Eds find Jimmy, scared by the sudden loss of daylight. Eddy pulls Jimmy's shirt apart by a loose thread, removing his outline in the process and causing him to melt away. Eddy then rearranges the outline and creates a new hairdo for his head. Ed is then shown sawing the sky and finds the Kankers in a bathtub. He pushes them away and Eddy then walks into the hole that fell on the ground and falls into it. Eddy then falls into the hole endlessly until Ed removes the hole from the ground. He then puts his head in the hole to see where it goes to, appearing up in the sky before he takes his head away from the hole. After seeing this, Edd notes that they are close to answering that all important question. Suddenly, Sarah appears from the rolled-up hole in Ed's hands, angry at what Eddy did to Jimmy, but Eddy gets rid of her with the help of some cartoon physics (by running fast in place and then stepping out of his spinning feet animation and placing Sarah on it causing her to run off very fast to places unknown).
Edd soon becomes excited over their discoveries, thinking they could make an appearance on the cover of "Intellectual Discoveries' Magazine". Eddy notes it is a good thing that Edd is housebroken. Edd then looks up and sees a cow floating in midair. Edd now becomes uncomfortable and walks away with Ed and Eddy following him. The boys are now in the midst of a realm where nothing is bound by Earthly limitations.
Sarah then comes out of a small house and claims that everything is broken and she wants Eddy to fix it now. Eddy tells Sarah to shut her mouth before deciding to physically remove her mouth. Eddy states he loves taking things apart, only for Sarah's mouth to start biting him. After Eddy asks Edd to get her biting-mouth off of him, the Eds disappear into an original scene transition that looks like a checkerboard. The Eds then appear in Kevin's eye, materialize from his bike's dust cloud, meet Jonny who has Plank for a head and is carrying his own head around, Nazz who has a large body of a purple reptile, briefly experience levitation, and Rolf with three heads coming from behind the wall revealing static.
The Eds escape after Ed inflates a cloud. They then start to ponder what to make of what they've discovered, but the cloud is popped from above by a pencil. The notepad is dropped, they hit the ground, and soon start grabbing the scattered notes.
Edd and Eddy realize that their setting is back to normal, but Ed seems to still think he can take off Jimmy's outline, Sarah's mouth, pick up holes, etc. The episode ends with Ed being pursued by Sarah, while carrying a sewer pipe which Edd and Eddy fell into.
At the beginning, when Eddy kicks Ed out of his bed and says "Get outta my room!" Eddy is seen with 4 toes instead of 3.
When the Eds take apart Rolf's chicken coop, Ed's body cannot be seen through the chicken wire.
When Rolf says "Life has many doors, Ed-boys!" His teeth are white instead of green.
When Eddy removes Jimmy's outline, his retainer outline is still on his body.
When Eddy places Jimmy's outline in front of Edd, the red stripe on Eddy's shirt is missing.
The line "Who turned off the sun?" was also used in "A Glass of Warm Ed," where Eddy says it rather than Jimmy.
Jimmy asking "Can't we all just get along?" is a reference to Rodney King and his public statement during the riots following his trial.
The fourth wall is broken four times:
Edd says "An original scene transition, interesting," when he sees a checkerboard scene transition. Likewise, the transition is similar in appearance to the original Cartoon Network logo, as well as the channel's Powerhouse bumpers from 1998-2004.
When Eddy pulls Jimmy's outline off, Edd says "Is that Jimmy's outline?"
A three-headed Rolf pulls the curtains open showing TV static in the background.
After Ed inflates the cloud, causing the boys to float into the sky, the cloud is popped by the tip of a pencil; a possible reference to the artist drawing the animation.
In this episode, Edd is shown to be ambidextrous, as he can be seen writing with both hands. This could, however, just be a goof.
Edd's line "This is not good!" after seeing Plank and Jonny's heads switched was identical to the line used in "Nagged to Ed."
When Ed asks "Eddy, why is someone in the kitchen with Dinah?" he is referencing a line from the song I've Been Working on the Railroad.
When Rolf pulls Wilfred out of the chicken coop, he says "Do not burn the candle at both ends, as it leads to the life of a hairdresser." This statement is contradicted in the episode "Take This Ed and Shove It," where Rolf reveals that he wishes to be a barber. He explains that "In the Old Country, he who cuts hair is viewed a man among men."
The scene of the Three-Headed Rolf popping out and saying his "many doors" quote has become a popular meme online.
"Where's the cash?!?" – Eddy Please consider downloading this episode of the show in high definition from iTunes in order to support the creators' hard work.