Participants in the study were 292 Grade 4 and Grade 5 students in 4 schools in the French-speaking Belgium. Two classes for each grade from each of the 4 schools were included in the study, one as a control group and the other as the experimental group. The control group received their regular mathematics lessons on fractions, while the intervention group received special instruction featuring the card games for 10 weeks. The students played different games twice a week for 30 minutes in small groups of three to five. Games increased in difficulty as the study proceeded. The games required that children add fractions, discern the highest value fraction or those of equivalent value and to compute the highest total value of a set of fractions.