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Exploring how matter can be measured and grouped by how big or heavy it is.
Have you ever tried to pick up a giant beach ball and realized it was lighter than a tiny rock? How can something so big feel so light, while something so small feels so heavy?
Size tells us how much space an object takes up. When we look at things, we can see if they are big, medium, or small. To sort things by size, we look at their height (how tall they are) and their width (how wide they are). We usually put things in order starting from the smallest and moving to the largest. Imagine lining up your shoes from your baby brother's tiny sneaker to your dad's big boot!
Let's sort these three fruits by size from smallest to largest: 1. A tiny blueberry. 2. A round orange. 3. A big watermelon.
The order is: Blueberry Orange Watermelon.
Quick Check
If you have a grape, a pumpkin, and an apple, which one is the largest?
Answer
The pumpkin is the largest.
Weight is a measure of how heavy something is. It is the 'pull' we feel when we lift something. We use words like heavy for things that are hard to lift and light for things that are easy to lift. We can compare weight by holding one object in each hand. The hand that drops down lower is holding the heavier object. Scientists use a balance scale to see which side is heavier. If the scale tips down, that side has more weight!
Imagine you are holding a feather in your left hand and a juice box in your right hand. 1. The feather feels like almost nothing. It is light. 2. The juice box pulls your hand down a little bit. It is heavy compared to the feather. 3. Because the juice box pulls harder, we say it has more weight.
Quick Check
If a balance scale tips down on the left side, is the object on the left heavier or lighter than the object on the right?
Answer
The object on the left is heavier.
Does 'bigger' always mean 'heavier'? No! Sometimes a small object can be very heavy, like a metal marble. Sometimes a large object can be very light, like a giant balloon filled with air. We have to be careful not to guess how heavy something is just by looking at its size. We must always test it by lifting it or using a scale to be sure!
Let's look at a giant pillow and a small brick. 1. The pillow is much larger in size than the brick. 2. However, the brick is made of heavy material, while the pillow is full of light fluff. 3. If you put them on a scale, the small brick would tip the scale down because it is heavier than the big pillow!
Which of these is the correct order from smallest to largest?
Which tool helps us see which of two objects is heavier?
True or False: A very large object is always heavier than a very small object.
Review Tomorrow
Tomorrow, look around your kitchen. Can you find one thing that is big but light, and one thing that is small but heavy?
Practice Activity
Find three different toys. First, line them up by size. Then, hold one in each hand to see if the order changes when you sort them by weight!