SATs exams are leaving schoolchildren "disengaged and stressed", according to some parents.
Thousands of children are being kept at home on Tuesday as part of a Let Our Kids Be Kids campaign against tests for six, seven and 11-year-olds.
Ben Ramalingam, who is keeping his five-year-old son off school, said some parents believe the situation is turning into a "mental health crisis".
"We are concerned parents taking a stand, we don't want our kids to be stressed out by the time they become teenagers because they have been inappropriately taught", he said.
"Our children are being pushed towards rote-based learning. It is like something out of Charles Dickens".
Jane Clout said: "I'm a grandmother and I sent my children through the state system in the late 1970s and early 1980s, and when I first started taking these boys to school I was struck by how primary schools have improved.
"But this is like going back to the 1950s".
Answer these sample questions to find out how you measure up against primary school pupils aged up to 11 years old.
Parents will be taking their children out of school tomorrow in an unprecedented "strike" against compulsory exams for six-year-olds.