science

Qian (mass)

Qian (mass) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Qian (mass) rather than just read about it. In short: Qian (simplified Chinese: 钱; traditional Chinese: 錢; pinyin: qián), called tsin (cin4) in Cantonese, tiền or đồng in Vietnamese, or "Chinese ounce" or "mace" in English, is a traditional Chinese unit for weight measurement. It originated in China before being introduced to neighboring countries in East Asia.

Key takeaways

Qian (mass) belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Qian (mass) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Qian (mass) from memory before moving on to harder problems.

Reference excerpt

Qian (simplified Chinese: 钱; traditional Chinese: 錢; pinyin: qián), called tsin (cin4) in Cantonese, tiền or đồng in Vietnamese, or "Chinese ounce" or "mace" in English, is a traditional Chinese unit for weight measurement. It originated in China before being introduced to neighboring countries in East Asia. Nowaday, the mass of 1 qian equals 5 grams in mainland China, 3.75 grams in Taiwan, 3.7799 grams in Hong Kong, Singapore and Malaysia, and 3.78 grams in Vietnam. Qian is mostly used in the traditional markets, and famous for measuring gold, silver and Chinese medicines.

In Japan, the equivalent mass unit to the qian is the momme.

China Mainland On June 25, 1959, the State Council of the People's Republic of China issued the "Order on the Unified Measurement System", retaining the market measure system, with minor amendment.

where 1 qian equals 5 grams, and 10 qiags equals 1 liang. The traditional Chinese medicine measurement system remains unchanged.

Taiwan In 1895, Taiwan was ceded to Japan from China. The Japanese implemented the metric system, but the Taiwanese still followed their own habits and continued to use the old weights and measures of the Qing Dynasty. 1 Taiwan qian is equal to 3.75 grams, or 1/10 Taiwan liang.

Hong Kong and Macau

Hong Kong and Macau mass units Currently, Hong Kong law stipulates that one qian is equal to 1/10 liang, which is 3.779936375 grams.

Similarly, Singapore law stipulates that one qian equals 3.7799 g. Malaysia has the same regulations as it is a former British colony as well.

Hong Kong troy units These are used for trading precious metals such as gold and silver.

Vietnam In Vietnam, the unit of qian is called "đồng or tiền": 1 đồng is equal to 3.78 grams or 10 phân by traditional value.

For more information on the Chinese mass measurement system, please see article Jin (mass).

See also Chinese units of measurement Hong Kong units of measurement Taiwanese units of measurement Vietnamese units of measurement

Notes

References

External links 中國度量衡#衡市制錢 (質量單位)

Worked examples

Example 1 — a first encounter with Qian (mass)

Start with the simplest possible case. Write down what Qian (mass) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Qian (mass) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Qian (mass) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Qian (mass)

In research: Qian (mass) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Qian (mass) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Qian (mass) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chinese units of measurement, Customary units of measurement, Units of mass, so understanding it makes those chapters shorter.
In everyday life: Look for Qian (mass) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Qian (mass) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Qian (mass) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Qian (mass) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Qian (mass) in simple terms?

Why does Qian (mass) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Qian (mass)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Qian (mass).