I think the problem might lie somewhere else. I just ran the following code:
%TEST := 50
%SCORE := %TEST / 10
$PAGETEXT := $PAGETEXT + "<p>" + %SCORE + "</p>"
%TEST := 60
%SCORE := %TEST / 10
$PAGETEXT := $PAGETEXT + "<p>" + %SCORE + "</p>"
%TEST := 70
%SCORE := %TEST / 10
$PAGETEXT := $PAGETEXT + "<p>" + %SCORE + "</p>"
...and got 5, 6, and 7 as output.