Random Number Generator

I found this great activity by Jose Ascarrunz which generates random numbers to solve equations. I’m trying to modify it so it only uses positive numbers. It looks like they’re set to be positive, but I get negative numbers when I preview. Here’s a link:

The only negative number I see is on the right-hand side of the equation for subtraction. That can be updated by changing x to depend on a in the component Problem. For example, change

x = numericValue("${r.int(2,10)}*${multiplier}")


x = when operation1=2 numericValue("${r.int(a,10)}*${multiplier}")
otherwise numericValue("${r.int(2,10)}*${multiplier}")

Thank you, so much!!