A question given to six-year-old children has left thousands of parents scratching their heads.
Assigned as a part of the maths homework to first-grade pupils in a primary school in Jiangsu Province, eastern China, the question involves five animals: a cat, a chicken, a pig, a rabbit and a cow.
It asks the pupil to choose one animal which is deemed different from the rest.
One parent took a picture of the homework and posted it to QQ, a Chinese chatting platform, reported the People's Daily Online.
The post has been quickly shared by web users since then, with thousands of parents debating over the correct answer.
Many people said on Chinese social media that the answer should be the cat because 'all the other animals are livestock and could be eaten'.
Others argued that the answer should be the chicken as it was the only animal that didn't have four legs.
One such post on Weibo, a Chinese social media platform, attracted nearly 3,000 comments since it went up yesterday.
A primary school maths teacher in Jiangsu Province, where the question originated, told a reporter from Pengcheng Evening News that the correct answer should be the chicken.
The teacher, surnamed Zhao, said: 'A chicken has two legs, all the other animals have four.'
Zhao also said a lot of parents tended to complicate simple questions given to small children.
The teacher said: 'Children's logic is different from adults'. Math questions given to first-grade pupils will reflect their logic.'
Farenuff, Perth, Australia, 2 hours ago
Looking at the first 2 questions, the number of legs is the defining difference.
Will Rogers1, Fort Collins, United States, 4 hours ago
Clearly the chicken...its bipedal with wings and feathers...duh! jk
dmentia, some dry town, United States, 7 hours ago
chicken - it was born in an egg and hatched to peck grain the others were live birthed and suckled... presumably
TheseViewsAreMyOwn, PNW, United States, 7 hours ago
It's the chicken - it's the only one without ears (pigs don't have fur; they have skin, so that doesn't work).
hoojah, Woodside, 7 hours ago
At first I thought it would be the cat as it's a non-food animal...then I remembered that it's China!
tangokilo, san antonio, United States, 8 hours ago
It is the chicken , all the others are mammals.
Maliboom, LaLaLand, United Kingdom, 10 hours ago
After reading the comments I feel a bit silly I didn't realise it's the chicken