Nedra visits the home of her brother George and tells him that it's been a year since his wife died, and the children need more than casual babysitters. Of the three children, Tom, Karen, and Anne, Anne in particularly has been upset and lacking guidance since her mother's death. The children are listening in and Anne runs upstairs, and Nedra confronts Karen and Tom, telling them she's not happy with how the family is going. She leaves and the children wonder if Nedra wants to take them away. George assures them she doesn't but admits that he's too busy to be there and provide them with the guidance and care they need full-time. Tom finds an advertisement for Facsimiles Unlimited, which proclaims "I Sing the Body Electric," an electrical data processing systems in the form of an elderly woman, who can provide care and love to families.
The family goes to the company offices where a salesman greets them and shows them displays of physical characteristics that they can choose for their electronic grandmother. Anne, angry, doesn't want a grandmother that resembles her dead mother and storms out. As George goes after her, Tom and Karen put together their "perfect" grandmother. Later, the new electronic grandmother arrives and introduces herself. They name her "Grandma" and she offers them a key to prove she's a real robot. She then helps them fly their kite, but Anne backs away. Grandma produces marbles for Tom but can only look in sorrow as Anne goes inside.
Later, George returns with a new car and reveals he's come home earlier for a surprise. He sends Tom and Karen out and talks to Grandma about Anne. She assures him that Anne will eventually accept her, but Anne comes down and insists she doesn't want Grandma there and never needed her. She hates her dead mother for lying to her, and hates Grandma. Anne runs away and Grandma goes after her to the park. She gets Anne to explain that she hated her mother by leaving her. Grandma gets Anne to finally admit that her mother died, that she let herself die. Anne walks into the street and a van approaches her. Grandma shoves her out of the way and the van runs her over. However, she gets back up, unharmed, and plays back Anne's words telling her to get away. Grandma explains that in the one way she's different in that she'll never leave them by dying. Reunited, the family goes back home together.
Eight years pass as Grandma loves and teaches the children. Finally as the children have grown up, Grandma bids them farewell as they go to college and explains that she will go back to the company where her mind will be transferred into a room of voices where she can share everything she learned from them. Grandma hopes that perhaps one day in the distant future she might receive the gift of life, but they assure her they've always thought she was alive. She sends them upstairs and then leaves, her task completed.