 Hello and welcome to the session. In this session we will discuss how to choose appropriate units of measurement. Now let us discuss how to choose appropriate units. Now there are different units for measuring length and weight like meter, kilometer, centimeter, millimeter, liter, kilogram, gram, meter etc. To find a suitable unit to measure you should first estimate how big it is. For example, for measuring the height of a mountain which measure is appropriate, kilometer or centimeter since mountain will be of large height. So we will use kilometer to measure its height and not centimeter. So for measuring the height of a mountain, kilometer is appropriate unit of measure. Now to measure weight of a truck which measure is appropriate ounces or tons. Now again we see that truck is heavy so we will use tons to measure its weight and not ounces because ounces are too light similarly to measure the volume of a test tube which unit will be used millimeter or liter. Now see since test tube is very small in size and it will work a small quantity of liquid so we will use millimeter and not liter to measure its volume. So for measuring volume of a test tube, millimeter will be used. Now let us discuss how to choose appropriate weights and units. Now it is important to choose appropriate units when you use a weight. You can express a weight in different ways by using various unit combinations that have the same meaning. The most useful way to express a weight depends on the problems you are solving. Furthermore, a unit weight can help you solve problems. Now we know that both inches and miles can be used to measure lengths. For example, the speedometer in your car read 30,000 inches per minute. Now in this example, we have measured the distance in inches that we can clearly judge that it is not appropriate measure to be used in measuring speed. Here inches does not give us a good idea of the speed of the car but if it reads 30 miles per hour then you have a better idea of how fast you are solving. So we can clearly see that miles per hour is an appropriate unit weight to measure speed. Now let us see one more example. Now suppose we want to find amount of food eaten by a bird each day. Now which unit weight we will use here? Ounces per day are, now see the amount of food eaten by a bird will not be very large. Bird will eat a small quantity of food and since ounces measure smaller quantities and measure heavier quantities than ounces per day is appropriate unit weight. Now let us see some of the common unit weights. Now to find average speed we use miles per hour. Now to find gas mileage we use miles per gallon and to find unit price whose price say dollars per pound. So in this session we have discussed all units of measurement and this completes our session. Hope you all have enjoyed the session.