A teaching union has welcomed extra funding for the least well-off pupils, announced as part of a deal on the Welsh government's budget.
Labour ministers won Liberal Democrat support by promising an additional £20m for the poorest children on Friday.
ATL Cymru said the money was good news for children from deprived backgrounds.
But the Conservatives and Plaid Cymru criticised the deal, which followed weeks of talks between ministers and opposition AMs.
The extra money boosts the size of a pupil deprivation grant to more than £32m next year.
Officials said £450 would go directly to schools for every child receiving free school meals.
There were 70,800 children entitled to free school meals in Wales last year.
ATL Cymru director Philip Dixon said: "The extra money will help schools boost the support they are giving to youngsters from deprived backgrounds, and go some way to closing the notorious funding gap in per pupil spend between Wales and England.
"Our children are our future and investment in them is investment for all. Both Labour and the Lib Dems deserve credit for ensuring that our children, especially those in most need, will now get a better start in life."
The two parties have also agreed on the destination of a £39m windfall which the Welsh government received as a result of a council tax freeze in England.
To be spent over two years, it includes more money for businesses that recruit young apprentices and capital spending for a home energy efficiency scheme.
Further details will be announced on Monday.
With 30 of the Senedd's 60 seats, Labour needed at least one opposition AM to ratify its £14.5bn budget.
Ministers had also been talking to Plaid Cymru, who called for increased spending to boost the economy.
The government had until Tuesday to table a final budget before a crucial vote on 6 December.
A Welsh government source indicated that Wales could receive a spending boost as a consequence of the Chancellor's autumn statement on Tuesday.
Any additional funds would be spent "in consultation" with the Lib Dems.
First Minister Carwyn Jones said other budget areas would not be cut to pay for the agreement.
Mr Jones told BBC Radio Wales: "This is about as much as we can manage, but it's money that is going to be used for a good purpose in order to provide better educational opportunities for some of our most deprived children."
Welsh Lib Dem leader Kirsty Williams said: "It would have been easier politically to walk away, but the Welsh Liberal Democrats have instead worked with our political opponents to agree a budget for the good of Wales."
Plaid Cymru said the Lib-Lab deal was "bad news for the Welsh economy".
The Conservatives, who wanted an increase in health spending, said the Lib Dems had "endorsed Labour's savage cuts to the NHS".