hi
your 3 to 2.40 would be correct.
because from 3.00 odds the tick difference is .02.
so from 3.00 to 2.40 is -30 alterations times .02(ticks)= -.60
so, if you want to go greater than -.60, you would be betting on anything above 2.40.
BUT, if you wanted to go below 2.40.
it would be less than -.60.
mcbee