if using a checkbox or toggle button then the values are stored as numbers - 0=false/no, -1=true/yes, so you can just add them up and multiply by -1 to convert to a positive number (or use the abs function)
note that in a continuous form the button should be bound or you would need to use some code in the button after update event.
Have an unbound txtTotal control in the form header or footer
in the button control after update event put
Code:
if btnControl then
txtControl=txtControl+1
else
txtControl=txtControl-1
end if
ensure all buttons are defaulted to 0 when the form opens