The pupils from Ysgol Emmanuel in Rhyl visited the Prime Minister's home to remind him of the promise world leaders made that every child in the world would have attended primary education by 2015.
With only seven years to go to meeting the Education Millennium Development Goal (MDG), 72 million children are still missing out on a primary education, with millions more forced to drop out of school before they can complete even a basic education.
Accompanied by Vale of Clwyd MP Chris Ruane MP the youngsters were the first school in Wales to deliver the "'missing out" cards.
The delegation delivered 471 "missing out" cards to No.10 to help put pressure on the UK government to get this target back on track.
Every pupil at Ysgol Emmanuel Primary had completed a card and colourfully illustrated what they would have missed out on if they had never been to school.
,The visit was part of the Send My Friend '08 campaign which is urging more schools to get involved and send their 'missing out' cards to the Prime Minister before 30 June when he flies off to Japan for this year's G8 Summit.