This means the contents of school bags across the country are worth nearly £1 billion, but are often being left unattended and used, for example, as goalposts for games of football.
New research released by the Money Advice Service revealed that one in 10 children aged six to 10 takes an electronic tablet to school, while over half of 11 to 16-year-olds take a smartphone. And 22% of mothers say their child's items are worth more than those they carry in their handbag.
Just 16% of parents have personal possessions insurance that covers all the contents of a school bag, while 50% of those with personal possessions insurance say they do not fully understand it, the study found.
The popularity of personal devices such as iPads, smartphones and MP3 players means schoolchildren carry, on average, at least one electronic item with them to school.
Despite 36% of parents saying they would be upset if their child lost their school bag and one in seven (14%) saying they would worry about the cost of replacing the items, 19% of parents know that their child leaves their school bag unattended in public places, and only the minority have adequate insurance cover.
Commenting on the findings, Jane Symonds, head of service delivery at the Money Advice Service said: "Electronic devices are so integral to our everyday lives now.
"It's incredible how quickly they have become 'must-have' items - even for children as young as six years old.
"It's easy to underestimate the cost of replacing them or to simply forget to update your existing insurance cover to include newly-purchased gadgets.
"Given how attached we get to essential items such as smartphones or e-readers, it's worrying how many parents don't fully understand which valuables are covered by their insurance policies.
"Our recent report - the Financial Capability of the UK - indicates that around half of all UK adults have home contents insurance. We urge everyone to consider which cover is right for them, because having unsuitable cover can be heart-breaking and costly if the worst happens.
"We advise parents with children heading back to school this autumn to take a moment to check what is and isn't covered, as well as the all-important details such as policy limits and excess amounts."
The survey found just 16% of UK parents have personal possessions insurance that covers all the contents of a school bag, and less than a quarter (23%) believe insurance is necessary, even though one in five (17%) is aware their child uses the school bag as a goalpost during games of football - something which is likely to be classed as 'negligence' by their insurers and could void a claim, researchers said.
In total, 2,000 UK parents of children aged between six to 16-years-old were surveyed.
The research asked parents of two age groups - six to 10 and 11-16-year olds - and showed that younger school children are not far behind their older peers in the gadget stakes.
The research found 9% of children aged six to 10 take a tablet device such as an iPad to school, compared to 11% in the older age group. Over half of 11 to 16-year-olds (57%) now take a smartphone to school, compared to 17% of six to 10-year-olds. The average value of electronic devices taken to school by six to 10-year-olds is £81, while it is £159 for those aged 11 to 16.
To put the figure in perspective, 22% of mothers say their child's school bags contents are worth more than the items they carry in their handbag and a quarter of fathers (25%) feel their child's bag carries items higher in value than their workbag or briefcase.
Across the country, school children in London carry bags with the highest average contents value at £138 - one in 10 (13%) of schoolchildren in the capital take iPads to school, while 8% take an e-reader.
The region with the lowest value is East Anglia, at £103, where a third of schoolchildren (34%) do not take any electronic devices to school with them at all.
The research also highlights a considerable lack of understanding amongst many parents as to whether their child's school bag contents are covered under other insurance policies.
Of those with home contents insurance, just a quarter (27%) say they fully understand what their policy covers, only 17% are certain their child's school bag is covered, and a third (31%) have no idea what it covers.
:: More information can be found at www.moneyadviceservice.org.uk