Photograph taken by Hervé Guérin in the main lobby of IBM France:
First we have to determine what IBM means by its famous slogan. Here are some of the many meanings of "think": "ponder; reflect (on); believe; consider; cogitate; feel; deem; hold; suppose; imagine; remember; recall; conceive; deliberate; recollect; evoke", etc. Thomas J. Watson, who led IBM from 1914 to 1956, first used this motto in December, 1911 at a sales meeting of a predecessor company, and he explained it as meaning "take everything into consideration".
Grammatically, the French "pensons" means "let's think", but I'll leave it to the Francophones who are listening in to tell us what special nuances that may convey. I personally do not believe that this is the Cartesian existential "je pense, donc je suis" ("cogito ergo sum"; "I think, therefore I am").
Now, the crux of this post is that the Chinese rènwéi 认为 ("consider; deem; hold; take to be", etc.) is wrong. It seems strange to see rènwéi 认为 ("consider; deem; hold; take to be", etc.) being used as the Chinese translation of the IBM motto "THINK".
When I was in high school, I was in awe of IBM as being at the vanguard of science. I subscribed to their magazine called THINK and devoured its every word, thinking / believing that it put me in touch with the most profound minds of the day.
Used as the IBM motto, "THINK" is a verb in the imperative mood. It bespeaks Thomas J. Watson enjoining his colleagues and employees to use their brains to improve the quality of their work and the productivity of the corporation.
Rènwéi 认为 ("consider; deem; hold; take to be", etc.) is a verb all right, but it's the wrong verb. It doesn't convey Watson's injunction to take everything into consideration. Rènwéi 认为 is usually used in sentences like this: "Wǒ rènwéi tā hěn liǎobùqǐ 我认为他很了不起" ("I think he's great; I consider him to be great"). In other words, SUBJ V OBJ PHRASE / CLAUSE, where the V is rènwéi 认为 ("consider; deem; hold; take to be") and the OBJ PHRASE / CLAUSE possesses verbal properties:
tā huì dāyìng 他会答应 ("he will agree")
tā huì jùjué 她会拒绝 ("she will refuse")
tā huì dǎyíng 他会打赢 ("he will win")
tā huì shībài 她会失败 ("she will lose")
tā hěn piàoliang 她很漂亮 ("she is beautiful")
tā hěn nánkàn 他很难看 ("he's ugly")
The IBM slogan, "THINK", on the other hand, does not take an object. It is just a simple command to someone to use their brain to perform a mental act.
Now, it's very interesting that the IBM motto "THINK" is regularly translated as sīwéi 思维 ("thinking; thought; cogitation; ratiocination") in Chinese, but I don't consider this to be a good translation either. Why? IBM's THINK is a verb in the imperative mood, whereas sīwéi 思维 ("thinking; thought; cogitation; ratiocination") is a noun (those who maintain that Chinese has neither lexical words nor grammatical parts of speech should take note).
I have also seen the IBM motto "THINK" rendered in Chinese simply as xiǎng 想 ("think; think of; suppose; miss [someone / something]; wish; believe; feel [like doing]; would like"). This is a verb, all right, but I don't think that it captures the spirit of Thomas J. Watson very well.
So what should the IBM motto be in Chinese? I honestly do not know for sure, but here are some possibilities (suggested by Hervé):
sīkǎo 思考 ("think [deeply]; ponder [over / on]; reflect [on]; cogitate; deliberate")
sīliang 思量 ("consider; turn something over in one's mind; ponder; weigh and consider")
kǎolǜ 考虑 ("consider; think [over / out]; size up; take into account; think about")
These are mostly used as verbs, but can also sometimes function as nouns.
My own tentative favorite is xiǎngyīxiǎng 想一想 ("think about it; think it over; give it due consideration; give it a / some thought"), but that's not very elegant.