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课件网) Unit 2 Section 4 Focusing culture, Cross-curricular connection, Project Amazing numbers 学习目标 I can understand the importance of numbers in daily life record and present information with numbers in English use cardinal and ordinal numbers correctly. understand how numbers developed and how they differ between cultures. 01 新 课 导 入 03 应 用 实 践 06 回 顾 总 结 07 随 堂 小 练 02 学 习 理 解 04 迁 移 创 新 05 考 点 速 递 学习内容 新课导入 1 People from different cultures use different numerals. Chinese numerals Roman numerals Arabic numerals 一 二 三 四 五 Before the invention of written numbers, people used many different ways to count things. What tools did people use to count things fingers stick 棍子 toes Tools to count numbers abacus Tools to count numbers written number system 书面数字系统 token 陶筹 clay 黏土 Do you know how numbers developed In ancient time, people used knots on ropes , stones or sticks to record numbers. Each stands for a thing we want to count. The development process of numbers Later, people replaced this system with abstract symbols. These were more convenient because they were quicker to write. In Chinese, such as five as “Ⅴ” and ten as “十”. V 十 The development process of numbers 10 In Arabic, such as five as “ ” and ten as “10”. Arabic numerals were invented in India not in Arab. This system was very popular at that time. Arabs spread to other parts of the world. So today, they are known as Arabic numerals. 阿拉伯数字 The development process of numbers 学习理解 02 How did numbers develop Think Focusing on culture Numbers are everywhere today. How did people in ancient time record numbers Let's explore the development of counting methods. Read an article from a science magazine and find out more about numbers. In ancient times, people developed different counting methods. One of the earliest was called “tally sticks(计数棍）” Each “stick” (or pebble 鹅卵石，or other counting tool) stands for a thing we want to count, such as an animal or a bag of rice. For each animal we want to count, we draw one stick. This is called a “one-to-one correspondence(对应）” Tally sticks are easy to understand, but it can take a long time to write down large numbers. To write 1,000, you have to draw a thousand tally sticks! Later, people created faster ways of writing numbers. One such system developed in ancient India. Instead of using tally sticks, people began using different abstract(抽象的) symbols to represent different numbers. Researchers do not know exactly how this happened, but some believe that the sticks slowly turned into symbols over the centuries. These Indian numerals(数字）became popular, and people in the Arab world started using them too. Thanks to the Arabs, this way of writing numbers spread to Europe and across the world. Nowadays, they are known as Arabic numerals. The ancient Romans wrote numbers in a different way. They used l ... ...
