Mathematics Ability: Ability to add and subtract two-digit numbers, multiply and divide 10's and 100's by 2, 3, 4 and 5, perform the four basic arithmetic operations with coins as part of a dollar, and perform operations with units such as inch, foot, yard, ounce, and pound. This category includes, but is not limited to, close proximity to moving mechanical parts, electrical current, elevated working surfaces, exposure to heat and exposure to chemicals (airborne and/or skin exposure).