A system for blending cement and at least one additive during a blending job to create a cement slurry for use in an underground hydrocarbon well includes a mixing tub, at least first and second blenders and a rotatable platform upon which the blenders are mounted. Each blender includes at least one elongated, rotatable, mixing blade extending into the tub to mix the cement and at the additive(s) to form the cement slurry.