A church school has caused anger amongst parents after it asked its pupils aged 10 to write down the worst swear words they know for their lesson on bullying.
The children are said to have filled their exercise books with racist and sexual obscenities, which their teacher got them to rank from "really upsetting" to "harmless".
One child rated f****r and c*** as "really upsetting" for a bullying victim, and words like p***head and fat a*** were as merely "upsetting".
"When my ten-year-old showed me a book with words like c***sucker rewarded with a tick from the teacher, I was disgusted," the Mirror quoted one parent as saying.
Adding: "You don't expect your children to learn this kind of filth at school, particularly one linked with the church."
Alison Evans, head teacher of Shelford C of E primary school near Cambridge, wrote a letter to parents apologising for the "inappropriate" lesson by teacher Fred Laband.
"The lesson was about the very important subject of bullying and the harmful effects of name calling," Evans wrote in the letter.
"One of the objectives was to understand that though some words may seem more or less upsetting than others, all name calling is hurtful.
"On reflection it has been agreed that it was inappropriate to record these words in writing and this page has now been removed from the children's books," she said.
The school governors said "experienced teacher" Laband had been disciplined but would not lose his job.
"It was ill-judged and won't happen again," chairman Alastair MacGregor added.