Back to: Computer Science Primary 3

*Welcome to class! I’m so happy you are here today!*

*In today’s class, we’re stepping into the past again to explore another early mechanical calculating device called the “Slide Rule.” It’s a bit different from the abacus, but equally fascinating. Let’s learn about it together!*

**History of Computer – Early mechanical calculating devices – Slides rule**

### What is a Slide Rule?

A slide rule is like a special ruler, but it’s not for measuring things like length or width. Instead, it helps us do math problems, especially multiplication, division, and even some complex stuff like science and engineering.

### How Does the Slide Rule Work?

The slide rule consists of two parts that can slide back and forth. It has numbers and scales marked on it. To use it, you place one set of numbers over another, and as you slide them, you can find the answer to a math problem.

For example, if you wanted to multiply 5 by 3, you would line up the 5 on one scale with the 3 on the other scale, and where they meet, you’ll find the answer, which is 15. It’s like a magic math tool!

### History of the Slide Rule

People have been using slide rules for a long time, even before we had modern computers. They were an essential tool for scientists, engineers, and students to do math and solve complex problems.

### Why the Slide Rule was Important

The slide rule was important because it made math faster and more accurate, just like the abacus. It helped people with scientific discoveries, building things, and solving real-world problems.

With the invention of modern calculators and computers, we don’t use slide rules as much today. But they have a special place in the history of math and science.

A slide rule is a tool for doing math, especially multiplication and division.

It consists of two sliding parts with numbers and scales.

People used slide rules for a long time, even before modern computers.

It made math faster and more accurate for scientists, engineers, and students.

Now, you’ve learned about the amazing slide rule. Keep exploring the world of computers and math, and you might become a math and science wizard one day!

We have come to the end of today’s class. I hope you enjoyed the class!

In the next class, we shall be discussing **Pascaline or Pascal calculator.**

In case you require further assistance or have any questions, feel free to ask in the comment section below, and trust us to respond as soon as possible. Cheers!

**Question Time**

- What is a slide rule, and what is its main purpose?
- How does a slide rule work to solve math problems, like multiplication and division?
- Why was the slide rule an important tool in history, especially for scientists and engineers?
- Can you give an example of how you would use a slide rule to perform a multiplication?
- What happened to the use of slide rules as modern computers and calculators were invented?
- How does the slide rule compare to the abacus in terms of its purpose and use in history?

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