Learning Resources Rainbow Fraction Measuring Cups (Set of 4). Rainbow Fraction Measuring Cups are a colourful, visual, 3D way to help young learners connect the concepts of fractions, volume, and capacity. These cups feature a bright colourful base that corresponds with the rest of the Rainbow Fractions teaching system resources, and transparent sides so children can see volume and capacity while learning fractional relationships. Includes 4 measuring cups (whole, 1/2, 1/3 and 1/4), and multilingual Activity Guide. Whole cup measures 9cm in diameter. Ages 3+.