four / 4

= + : Mnemonic symbol: a four-leaved clover. Socrates (s) is working out in the bathroom of the space station (Ø4). He's lifting four (四) wooden boxes (囗), and wonders why they are so heavy. He doesn't know that inside one of the four boxes, the monkey king (儿) is hiding and secretly laughing at him - until the monkey king comes out and surprises Socrates with a four-leaved clover (四).

四 character breakdown

variant of 人[ren2] / "person" radical in Chinese characters (Kangxi radical 10), occurring in 兒, 兀, 兄 etc
child / son

= 丿 + : Mnemonic symbol: "son" (儿) sounds similar to "Sun" like in "Sun Wu Kong", so it's gonna be represented by the monkey king. Albert Einstein (Ø-) and Sun Wu Kong (儿) are fighting in the space station's kitchen (-Ø2). Their weapons: Albert Einstein has a shovel (乚), and Sun Wu Kong has a banana (丿).
non-syllabic diminutive suffix / retroflex final
enclosure

Mnemonic symbol: a plastic enclosure. Willy Walrus (w) is keeping frozen fish in an enclosure (囗) in the Eiffel Tower's kitchen (ei2).

Characters with 四 as component

river in Shandong
nasal mucus
team of 4 horses
to rest
spoon / ladle

Words with 四

the four basic operations of arithmetic (addition, subtraction, multiplication and division)
abbr. for 四個現代化|四个现代化[si4 ge4 xian4 dai4 hua4], Deng Xiaoping's four modernizations
The Sutra in Forty-two Sections Spoken by the Buddha, the first Chinese Buddhist text, translated in 67 AD by Kasyapa-Matanga 迦葉摩騰|迦叶摩腾[Jia1 ye4 Mo2 teng2] and Gobharana 竺法蘭|竺法兰[Zhu2 fa3 lan2] (Dharmaraksha)
Shikoku (one of the four main islands of Japan)
all around / on all sides / encircled
all the borders
Four Sacred Mountains of Buddhism, namely: Mt Wutai 五臺山|五台山 in Shanxi, Mt Emei 峨眉山 in Sichuan, Mt Jiuhua 九華山|九华山 in Anhui, Mt Potala 普陀山 in Zhejiang
the Four Classic Novels of Chinese literature, namely: A Dream of Red Mansions 紅樓夢|红楼梦[Hong2 lou2 Meng4], Romance of Three Kingdoms 三國演義|三国演义[San1 guo2 Yan3 yi4], Water Margin 水滸傳|水浒传[Shui3 hu3 Zhuan4], Journey to the West 西遊記|西游记[Xi1 you2 Ji4]

Sentences with 四