Several parts combine into one character.

In oracle bone script, 七 was a plus sign — a vertical stroke crossed by a horizontal one — and meant "to cut / cleave". The character was repurposed phonetically to write the number seven, and a new character 切 (still meaning "cut") was created later by adding 刀 (knife) to the original. So 七 is a fossilized loan: a knife symbol used for an unrelated number. The bottom hook in modern 七 is a stylized cut-mark. Identical across 繁體 / 新字体 / 简体.

Seven carries mixed cultural weight. The constellation 北斗七星 (Big Dipper / Plough — "Northern Bushel Seven Stars") is a navigational and divination focus across East Asia. The 七夕 (qīxī / tanabata) festival on the seventh day of the seventh lunar month celebrates the once-yearly meeting of two star-crossed lovers (the Cowherd and the Weaver Girl) — basically the East Asian Valentine's Day. In Buddhist tradition, the soul wanders for 49 days (7×7) after death.

Mandarin: qī, level 1st tone. 七月 (qīyuè, July), 七十 (qīshí, seventy). Number 7 is generally considered slightly lucky in Mandarin-speaking culture — not as auspicious as 6 or 8, but positive.

Japanese: on-reading シチ (shichi) — but again the dual-reading rule kicks in to avoid death-syllable confusion (シ in シチ shares the death sound). Many speakers use kun-reading なな (nana) for clarity: 七時 reads either しちじ (shichiji) or ななじ (nanaji); 七人 (shichinin or nananin). 七つ (nanatsu, seven items). This dual-reading habit, born of cultural caution, is one of the genuinely difficult parts of Japanese number-fluency.

Financial form: 漆 (also lacquer/paint character — homograph).

Memory aid: a horizontal line crossed by a hooked vertical — the original cut mark, repurposed.