Why do JLPT N4 learners confuse 億 with うち?

Both words occupy adjacent semantic territory, which is exactly why the JLPT uses them as distractors for each other on multiple-choice items. The fastest way to stop confusing them is to study them as a pair, write a one-sentence contrast in your own words, and drill the pair specifically rather than each word in isolation.

Is 億 or うち more common on JLPT N4?

Both appear in the JLPT N4 curriculum and either may show up on a given exam. Don't try to predict which one the test will choose — learn to distinguish them and you'll be safe regardless. Both belong to the General Nouns theme of N4 vocabulary.

How do I practice this confusion pair?

Free option: visit /try and pick a confusion drill. Paid option: none — JLPT Mastery is free during launch. Whichever route you take, the engine specifically re-tests pairs you've gotten wrong rather than rotating through general vocabulary review.

JLPT N4 · Elementary · Meaning confusion

億 vs うち

Q: What's the difference between 億 and うち?

億 (おく) means "one hundred million" and うち (うち) means "within". Learners may confuse the boundary 'within a hundred million' with the number itself. The radical for person (亻) in related counting kanji can also be visually overwhelming for beginners.

Why JLPT N4 learners mix up 億 (おく, “one hundred million”) and うち (うち, “within”).

億

おく

one hundred million

noun

うち

within

noun

Theme: General NounsJLPT N4

Why these get confused

Learners may confuse the boundary 'within a hundred million' with the number itself. The radical for person (亻) in related counting kanji can also be visually overwhelming for beginners.

How to tell them apart

Anchor on the meaning, not the form. 億 (one hundred million) and うち (within) live in adjacent semantic territory. Memorize the boundary, not just each word.
Read the example sentences below. Seeing each word in its natural context builds a faster lookup than studying the dictionary form alone.

In a sentence

億 (one hundred million)

トムは億万長者だ。
空には何十億もの星がある。

うち (within)

うちへ帰ります。
これがうちです。

How JLPT tests this pair

On JLPT N4, this pair shows up as a vocabulary meaning question. You see one word and pick its English equivalent from four options — one of which will be the other word in this pair, chosen as a distractor precisely because of the overlap.

Sample item

「億」の意味は？