Mum Louise Bloxham tweeted a photo of the task that involved working out how many people were on a train.
The question states: "There were some people on a train. 19 people get off the train at the first stop. 17 people get on the train.
"Now there are 63 people on the train. How many people were on the train to begin with?"
The photo was then picked up by the Facebook page 'Parents Against Primary Testing'.
Parents on both Twitter and Facebook were outraged that the question has been written for six and seven-year-olds.
Some parents argued that they could only just work it out themselves, let alone their children.
Others argued the question was "ambiguous" and a "trick" for children taking a test.
"The published answer for this is 65, so continue debating whether this is too hard," the people running the Parents against Primary Testing Facebook page wrote.
The news of the challenging question comes after parents claimed children were coming out of their exams "in tears" because the test was so hard on Monday 9 May.