Dwire+March+Math+Weight

For the last couple of weeks we have discussed the term length and talked about different ways to tell if things were short or long. Looking at this picture, can you tell me which of the objects is shortest? What about longest? How could you tell?

This week for math we are going to talk weight and how to tell which objects are heavier or lighter. First, let's go over the terms we need to know.

The word heavier means more than the usual or average weight. (compare two objects on the scale and show that one is heavier than the other)

Lighter means less than the usual or average weight. (compare two objects on the scale and show that one is lighter than the other)

Knowing if things are heavy or light will help us plan our day and trips better. For example, if we are going over to McAuliffe and need to take supplies with us, it's good to know which ones are heavier or lighter so we know what to take with us.

One way to tell if an object is heavy or light is to look at them. Sometimes a bigger object is heavier than a smaller object. Can you circle the objects that are heavier? (erase and do again with lighter) Lets test this out on the scale. (show 2 example of bigger objects weighing more) Why is the balance pan for (item A) lower than (item b)? ("item A" is heavier than "item b").

(show 3rd example of smaller object weighing more, then ask classes what happened).

Is looking at an object always the best way to see if an object weighs more? (Not always). Sometimes we need to use scales to help of see how heavy things are so we can know if we are able to safely handle an object,

(use scale to weigh different objects in the room).

Let's look at the picture. We are going to weigh these objects and a box of crayons at the same time. Can you make a guess as to which one you think is heavier? (have students come to the front and write an H for the object they think will be heavier and an L for the object they think will be lighter. After all predictions are made, weigh items vs. a crayon box and compare answers with the students).

What did this balance help us to see? (which item is heavier or lighter) How do you use it? (put an object on each pan) What if we don't have a balance, is there something else we can use? (Your hands, have students try).