Bribing your child with a chocolate bar to finish his or her maths homework is an excellent idea, according to researchers who claim that the yummy treat could improve the brain's ability to do the most "dreadful" subject.
The study, presented at the British Psychological Society annual conference, is great news for students who binge on chocolate when revising for exams.
For the study 30 volunteers were asked to count backwards in groups of three from a random number between 800 and 999 generated by a computer.
The findings show that they could do the calculations more quickly and more accurately after they had been given the drink.
However, the same was not true when the group was asked to count backwards in groups of seven, which the researchers described as a more complex task, requiring a slightly different part of the brain.
The findings also show that the volunteers did not get as tired doing the calculations if they had been given the cocoa drink, despite being asked to do them over and over for an hour.
The flavanols work by increasing the flow of blood into the brain. Dark chocolate contains higher quantaties of the chemical than plain or milk chocolate.
Prof David Kennedy at Northumbria University said that chocolate could be beneficial for mentally challenging tasks.
The researchers gave the volunteers a total of 500mg of flavanol.
Although the amount was too great to be found naturally in the diet, researchers said that people should ensure that they have lots of flavanols.