Time and Measurement Whitaker 3rd Grade

A long time ago, people didn’t have clocks like we do today, but they still needed to know the time! Here's how they did it:

History of Time

The Sun and the shadows

The first way people told time was by looking at the sun. When the sun rose, it was morning; when it set, it was night. They also used shadows. People would put a stick in the ground and watch how the shadow moved as the sun moved across the sky. This was called a sundial.

Water Clocks

Water Clocks: Later, people made water clocks. They would let water drip slowly from one container to another. When the container was full, a certain amount of time had passed.

Hour Glass

Hourglasses: Then came the hourglass. These are those cool glass shapes with sand inside. As the sand trickled from the top to the bottom, people could measure time, like for an hour or a few minutes.

Mechanical Clocks

Mechanical Clocks: Many years later, people invented mechanical clocks. These clocks had gears and springs inside. They would tick and tock and use moving hands to show the time.

Modern Clocks

Modern Clocks: Today, we use digital clocks and watches. They run on batteries or electricity and can be super accurate. Some clocks even connect to satellites or the internet to always show the right time!

Famous Clocks

Big Ben (London, UK): One of the most famous clocks, located in a tower next to the Houses of Parliament. It has a large, beautiful clock face and rings with a big bell every hour.Astronomical Clock (Prague, Czech Republic): This clock is very old and special. It shows the time, the position of the sun and moon, and even has moving figures that come out every hour.Clock Tower (Mecca, Saudi Arabia): This is one of the tallest clock towers in the world. It stands next to the famous Kaaba and has a huge clock face that can be seen from far away.Glockenspiel Clock (Munich, Germany): This clock is in a tall tower, and every day, little figures come out and "dance" when the clock chimes.Peace Tower Clock (Ottawa, Canada): This clock is on top of the Canadian Parliament building and is a symbol of peace. It has a big bell that rings every hour.

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Types of Scales

Metric Vs. Customary

• Metric System:
• meter (m), milimeter (mm), centimeter (cm), Liter (L), mililiter (ML), Kilogram (Kg), gram (g)
• Simple to use: based on the number 10, 100s, 1,000
• Used in most countries around the world

• uses a wide range of units including miles, feet, inches, pounds, ounces, quarts, and gallons
• Based on older measurements
• Harder to convert- not base 10 numbers
• Used mostly in United States

Balance Scale

The traditional balance scale consists of two plates or bowls suspended at equal distances from a fulcrum. This scale has two sides. You put the object on one side and weights on the other side. When both sides are level, you know how much the object weighs.This is how humans first began weighing items!

The oldest evidence for the existence of weighing scales dates to c. 2400–1800 BC in the Indus River valley. Ancient people used stones to balance objects in order to measure their weight.

Spring Scale

A spring scale is a tool used to measure how heavy something is. It has a hook at the bottom where you hang an object. Inside, there's a spring that stretches when you hang something on the hook. The heavier the object, the more the spring stretches. The scale has numbers on the side to show how much the object weighs. So, you just hang the object on the hook, and the spring stretches to show you the weight!

Digital Scale

Digital Scale: A digital scale is like a flat surface. You put the object on it, and the scale shows the weight on a screen in numbers.A digital scale works by using special sensors inside. When you put something on the scale, the sensors feel how heavy the object is. Then, the scale turns that information into a number and shows it on the screen. It's quick and easy because you just put the object on the scale, and it tells you the weight!