For 1. To estimate how many sports cards Alberto had, you would round each number to the nearest ten, so 318 would become 320. 273 would then become 270. You would then add those two and would get 590. So, Alberto had 590 sports cards (estimated). If you were looking for the actual answer (not estimated) , you would get 591.
All except 0. The inequality is saying that x must be less than or equal to 3 which all answers except 0 are.
0.5 is 50%
0.12 is 12%
0.155 is 15.5%
A $36 item is 25% off. This means we can multiply 36 by 0.25 to find out how big the discount is.
$36*0.25=$9
