subtract

sub-,在下，向下，-tract,拉，词源同 attract,contract.引申数学名词减，减去。

subtract

subtract: [16] To subtract something is etymologically to ‘pull it away’. The word comes from subtractus, the past participle of Latin subtrahere ‘pull away’. This was a compound verb formed from the prefix sub-, usually ‘under’ but here used in the sense ‘away’, and trahere ‘pull’ (source of English traction, tractor, trait, etc). The strictly mathematical use of the word is a post-Latin development.
=> contract, retract, traction, tractor, trait

subtract (v.)

1530s, "withdraw, withhold, take away, deduct," a back-formation from subtraction (q.v.), or else from Latin subtractus, past participle of subtrahere "take away, draw off." Related: Subtracted; subtracting. Mathematical calculation sense is from 1550s. Earlier verb form was subtraien (early 15c. in the mathematical sense), which is directly from the Latin verb.

Here he teches þe Craft how þou schalt know, whan þou hast subtrayd, wheþer þou hast wel ydo or no. ["Craft of Numbering," c. 1425]

1. Please subtract a quarter of the money for your own use.

请从你的零用钱中扣除四分之一.

2. Subtract four from nine and you have five.

九减四得五.

3. In their first year at school, most children learn to add and subtract.

入学第一年, 多数孩子都学加减法.

4. When you subtract two numbers, you subtract a subtrahend from a minuend.

当你作两个数的减法时, 你用一个被减数去减另一个减数.

5. The little girl has begun to learn to add and subtract.

这小女孩已在学做加减法了.