Levers types - Type 1 Lever, the pivot (fulcrum) is between the effort and the load. In an off-center type one lever, the load is larger than the effort, but is moved through a smaller distance.Type 2 Lever, the load is between the pivot (fulcrum) and the effort. Type 3 Lever, the effort is between the pivot (fulcrum) and the load.Pulley systems - A fixed pulley is the only pulley that when used individually, uses more effort than the load to lift the load from the ground. A movable pulley is a pulley that moves with the load. A movable pulley allows the effort to be less than the weight of the load. The movable pulley also acts as a second class lever. The load is between the fulcrum and the effort, A combined pulley makes life easier as the effort needed to lift the load is less than half the weight of the load. The main advantage of this pulley is that the amount of effort is less than half of the loadWheels and axle-A wheel and axle is really two machines in one. The first way is to roll something along,The second way of using a wheel is like a lever in the roundMechanical Advantage Mechanical Advantage is equal to the output force divided by the input force or the Input distance/displacement divided by the output distance/displacement.Efficiency- The MA may be calculated from the ratio of the forces involved or from the ratio of the distances through which they move. Ideally, the two ratios are equal, and it is simpler to calculate the ratio of the distance the effort moves to the distance the resistance moves; this is called the ideal mechanical advantage (IMA). In any real machine some of the effort is used to overcome friction. Thus, the ratio of the resistance force to the effort, called the actual mechanical advantage (AMA), is less than the IMA. Another fun link on simple machines Ms.A's homeschool group suggestion       