Find the greatest number you can add to 4315 without having to regroup how did you find the number

Acircle has a circumference of 28.36 units what is the diameter of the circle

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.