Answer: CODAP graphs can only bin one numerical axis. But you can create bins formulaically for a second numeric attribute as shown here. This document randomly generated values for Height and Weight and a slider named interval to control the bin width for a third attribute named Weight_binned. The formula for Weight_binned is
floor(Weight/interval)*interval+" to " +ceil(Weight/interval)*interval
The enclosed screenshot shows the result plot with both numeric attributes binned.
