Two rulers are made to slide over each other to explain addition as putting together of two numbers and subtraction as taking away of second number from first number. Playing with the ruler helps children to do variety of operations numerous times and hence enhances speed and accuracy. This logic is extended in the other side of sliding ruler to explain addition and subtraction of fractional numbers. Playing with fractional side of number system helps children in understanding and using concept of equivalent fractions.
Learning Outcome: Successor and predecessor, addition and subtraction, whole and part, equivalent fractions, addition and subtraction of fractions