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课件网) 沪教版八年级上 Unit 2 Amazing numbers Section 4 focusing culture &Cross-curricular connection&Project 1 Lead in 2 Focusing culture 3 Cross-curricular connection 4 Project 目录 CONTENTS Lead in Before the invention of written numbers, people used many different tools to count things. What other tools did people use to count things Brainstorm Observe and say fingers toes marks on sticks and bones tokens（ 代币） made from clay（黏土） or small stones abacus The babylonians（巴比伦人） used clay to record transactions（交易情况）. In ancient China, people used the number of stones to count the number of objects. One stone means one, two stones mean two and so on. Marks &Tokens Focusing culture 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! tally sticks for one - to - one counting for large numbers (e.g., writing 1,000 needs 1,000 marks). 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. stick counting Ancient India abstract symbols Indian numerals popularity Arab - world adoption Spread to Europe & world Modern Arabic numerals 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. Tally - stick counting Indian abstract symbols Arab - world adoption Global Arab ... ...
