It all started when teacher Chris Mayo, founder of Sweet Counter, forgot the straws she used to teach place value. As a substitute, she cut out cards at coffee-time: jars of sweets for 100s, boxes for 10s and individual sweets for units.
"Eyes began to light up as they saw the concept and understood the value of numbers," says Ms Mayo. "We soon developed a range of colourful card resources for number and language work."
Larger, stronger and longer lasting Playground Pictures take the colourful creations out into the playground, where they can be glued, screwed or nailed to walls and fences.
Teachers talk about consonant clusters and digraphs. Little ones want to know how many eyes the alien has and how many frogs are sitting on the log.
"The cards use a currency that children understand," says Ms Mayo.