【问】 请讲一讲数学符号在英语里的读法。
 【答】 下面是一些最常见的数学符号的读法：
 + plus;positive(a+b=c)
 - minus;negative
 ± plus or minus(the square root of 4a² is±2a)
 × multiplied by; times (6×4=24)
 ÷ or： divided by(24÷6=4)
 ＝ equals(6+2=8)
 ≠or≠is not equal to
 > is greater than(6>5)
 >> is much greater than
 < is less than(3<4)
 << is much less than
 ≧ or ≥ is greater than or equal to
 ≦ or ≤ is less than or equal to
 ≯ is not greater than
 ≮ is not less than
 ≈ is approximately equal to
 ≡ is identical to
 ～ equivalent;similar
 ≅ is congruent to
 ∝ varies directly as; is proportional to
 ： is to; the ratio of
 ∴ therefore
 ∞ infinity
 ∠ angle; the angle(∠ABC)
 L right angle(LABC)
 ⊥ the perpendicular：is perpendicular to(AB⊥CD)
 ‖ parallel; is parallel to(AB ‖CD)
 ⊙or ○ circle
  arc of a circle
 △ triangle
 □ square
 ▭ rectangle