If 27 ewes each had eight babies, how many lambs would you end up with? Counting sheep may help you to get to sleep at night, but practising more complex sums before bedtime can improve your maths skills, a study has found.
Most people can quickly recall that three sevens are 21 and six sixes make 36, but few will have learnt their 26, 29 or 33 times tables by rote.
Researchers from the universities of Leicester and Loughborough set out to examine whether the time of day at which people solve maths problems has any effect on how easily they are remembered, choosing sums that multiplied the numbers between 22 and 33 by six, seven, eight and nine.
With enough time many people could work out that 27 times eight equals 216, but most would find it hard to instantly recall the answer from memory.
The researchers took 77 adults based in the UK, aged between 18 and 40, and set them the task of learning a set of sums.
In the first experiment they were asked to learn them between 8pm and 10.45pm before going to bed. They were tested on the answers the next morning, about ten hours after having learnt them.
In the second experiment they were asked to learn the sums between 7.30am and 10am and were tested ten hours later, having spent the day awake.
Participants had to provide the answer to each sum within six seconds to ensure they were recalling the solution from memory rather than working it out.
The study, published in the journal Royal Society Open Science, found that those who learnt the sums before bedtime fared better, scoring an average of 20.7 out of 28 compared with 18.5 for those who learnt them in the morning.
The research concluded: “This study has identified a beneficial effect of learning prior to sleep on recall of complex multiplication problems compared with learning these problems during the daytime. Future research should explore whether similar effects are observed with children learning simple multiplication facts.”
Times tables before bed
The researchers noted: “The beneficial effects of sleep on memory are well established. Sleep supports the consolidation of learnt facts.” They suggested that, during sleep, the things we have learnt are transferred from our short-term to our long-term memory banks.
The study said: “The active consolidation system hypothesis — in which declarative memories [such as facts, names and places] in the hippocampus are reactivated and transferred to the neocortex, driven by slow wave sleep oscillations — would suggest that the transfer of arithmetic facts to long-term memory in the neocortex is optimised when learning is followed by a period of sleep, compared with a period of wakefulness.”
The findings could be useful for children learning simpler sums, the researchers suggested, raising the prospect that a quick run-through of the times tables before bedtime could help a child to memorise them.
The study concluded: “The present study indicated that learning prior to sleep benefits learners at all levels of initial learning . . . This suggests that targeting learning of multiplication problems prior to sleep could benefit learners with varying memory capacities and prior knowledge of multiplication.”
