Answer:
1 tick mark represents 0.25 unit
Step-by-step explanation:
it goes -2.5 (tick) -2 (tick) -1.5 (tick) -1 (tick) -0.5 (tick) 0
take 2 adjacent points
1 tick mark = -2.0 -(-2.5) = +0.5 or
+0.5 - 0 = +0.5
