A family using one phone between six children for schoolwork said a donated tablet had "made a big difference".
Michelle Holgate from Swindon said while they were off school during the coronavirus lockdown she allocated them each one hour sessions with the phone.
She said one was "so stressed, saying she's going to fail everything".
Research carried out by Lloyds Bank has shown an estimated million children and young people have no adequate access to devices or the internet at home.
The Holgate family said the tablet, donated by a BBC viewer who saw the family's plight highlighted on regional news programme Points West, meant the children could now "produce better work".
Before that, they were allocated small amounts of time online by mother Michelle.
The children have been set new work each week online but said it was hard for them to keep up.
Since schools closed in March, families in the most deprived areas have been hit the hardest as the digital divide opened up between the haves and have-nots.
Research showed the problems one million children in the UK have getting online.
In addition, it is estimated about 700,000 young children do not have the skills and devices that they need to do their homework
A Department for Education (DfE) spokesperson said the government had been "clear in its commitment that no child should fall behind as a result of coronavirus".
"Which is why we have provided over £100m to support children to learn at home, including delivery of over 200,000 laptops and tablets," the spokesperson added.
It has also partnered with BT to provide low-income families with free access to the web on up to three devices at a time for six months.
Richard Johnson, the head of Gloucestershire's Severn Vale school, applied for laptops under the government's scheme and has been given seven.
"We know about 50% are using their phones and the digital divide is growing," said Mr Johnson.
Many charities and companies have set up schemes to accept donations of old laptops, tablets and phones which they refurbish then supply to schools for pupils.
Charlie, 14, who is due to sit his GCSEs in 2021, has been doing all his homework on a phone.
"I'm finding it very, very stressful and to be honest sometimes I find it all too much and I don't do any work at all," he said.
Schools are due to reopen in September and the DfE said it had launched a £1bn Covid catch-up fund "to directly tackle the impact of lost teaching time as a result of the pandemic".
Anyone who has a device they would like to donate can visit the BBC's Make A Difference website to find out how to donate and what equipment is required.