You are using string array. However, I think you only need to show one of the element at a time.
You can try to use
[code]
if (step<(n2-1) ) {
scaffoldtxt="Largest number that can multiply "+ i1 +" that is =< "+tv[2*step+1]+" ? "; 
scaffoldtxt1="Largest number that can multiply "+ i1 +"*"+(int)(Math.pow(10,(int)(Math.log(i2/100)
}
[/code]