science

Hao (length)

Hao (length) 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 Hao (length) rather than just read about it. In short: The Hao (Chinese: 毫; pinyin: háo) in Mandarin, or hou in Cantonese, is a traditional Chinese unit of length. One hao equals 1/10 of a li, 1/10000 of a chi, or 33+1⁄3 μm.

Key takeaways

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

Reference excerpt

The Hao (Chinese: 毫; pinyin: háo) in Mandarin, or hou in Cantonese, is a traditional Chinese unit of length. One hao equals 1/10 of a li, 1/10000 of a chi, or 33+1⁄3 μm.

Chinese length units promulgated in 1915

Present law on Chinese length units

This law of length measurement was issued by the Chinese government in 1929, and has been effective since 1 January 1930. The base unit chi is defined to be 1/3 meter.

Chinese length units in engineering These units are based on the metric system. The Chinese word for metre is 米 mǐ, which can take the Chinese standard SI prefixes (for "kilo-", "centi-", etc.). In the engineering field, traditional units are rounded up to metric units.

Compounds 絲毫 (sīháo) 一絲一毫 (yīsīyīháo) 差之毫釐，謬以千里 (chāzhīháolí, miùyǐqiānlǐ)

See also Li (short) Chinese units of measurement

References

Illustrations

Worked examples

Example 1 — a first encounter with Hao (length)

Start with the simplest possible case. Write down what Hao (length) 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 Hao (length) 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 Hao (length) 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 Hao (length)

In research: Hao (length) 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 Hao (length) 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: Hao (length) 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 length, so understanding it makes those chapters shorter.
In everyday life: Look for Hao (length) 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Hao (length)” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Hao (length) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hao (length) 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 Hao (length) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hao (length) in simple terms?

The Hao (Chinese: 毫; pinyin: háo) in Mandarin, or hou in Cantonese, is a traditional Chinese unit of length. One hao equals 1/10 of a li, 1/10000 of a chi, or 33+1⁄3 μm.

Why does Hao (length) 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 Hao (length)?

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 Hao (length).