CHAPTER 1 2 Why do scientists measure Why

CHAPTER 1. 2 Why do scientists measure?

Why are measurements important? We can’t always depend on our own eyes only Measurements help us collect exact information Exact measurements are especially important for scientists

What is an unit? Unit is a known amount used for measuring. Examples: inch, lbs, mile, yard, minute, hour OR: Examples: cm, g, km, minute, hour

Unit of measurement English System In America and Myanmar. Examples: inch, lbs, mile, yard, minute, hour. Metric System Most of the world: Europe, Asia, Africa. Examples: cm, g, km, minute, hour.

What do scientists use to measure length, width, height, volume, mass, weight and temperature? ? THE METRIC SYSTEM

History 1. Thousands years ago, people used their parts of body for measurements. For example, Egyptians used the cubit to measure length. The cubit was the distance from the elbow to the tip of the middle finger. 2. The Romans used the width of their thumb to measure length. It was called an uncia.

Why it didn’t work? Body parts have different measurements. Everyone has different width of thumb. So, the measurements are NOT accurate. That’s why, people invented a standard system of measurements so everyone has the same measurement.

Why do scientists need to use a standard system of measurement? In order for a unit of measurement to be useful, it has to be the same for everybody. Measurement should mean the same thing to scientists who share data

Self-check page 8 1. 2. 3. 4. Why are measurements important? Why is it important to use units of measurements (same system) that are the same for everyone? What are some common units in the English system of measurements? What is the name of the system of measurement that scientists use?