Reading Mathsin English

Functions: those strange machines

Unit 3 ACTIVITY 1

1st Part:1st Part:

GENERALDIFFERENCES

Mathematical notation aspires to be universal. But there are some differences between Catalans and English-spoken people when writing Mathematics.

They are not important differences (it is a question of style, we can say). But it is interesting to know them.

1. Writing numbers The English “seven” is like the one on the computers or the calculator:

It can’t be confused with a “one”, because the English one is:

Catalan seventeen: English seventeen:

2. Decimal point To separate the whole part from the

decimal part of a number, the British people use a point, not a comma:

7·25 “seven point twenty-five” or “seven point two five”

It is not a bad solution because, in this way, they don’t confuse the decimals points with the commas, working with ordinate pairs (x, y):

Catalan notation: British notation:P ( 2,3 , 5,8 ) P (2·3, 5·8)

3. Multiplication symbol As they can’t use the point to express

product, the British always use an oblique cross:

7×25 “seven times twenty-five”

They use this symbol, even, working in Algebra:

Catalan expressions: British expressions:7a, 2ab 7×a, 7×a×b

4. Using variables It is even more complicated when we

are working with equations, as the product symbol can be confused with the unknown number “ecs” (variable). To solve this problem, they use a kind of italics:

Catalan expressions: British expressions:

4x, -3x2 4×x, -3×x2

5. Equality symbol As we do, the British people use the

equality symbol in different situations. But they distinguish well:* Doing calculus: 7+8×2-5 = 7+16-5

(always new line) = 23-5 = 18

* Solving equations: 5×x-7=3×x+9 5×x-3×x=9+7

2×x=16(always new line, and symbol ) x=8

6. Division symbol English-spoken people don’t

understand the colon (:) as the symbol of the division. They use ÷ :

The colon is only used to express ratio:

12÷3 “twelve divided by 3”

2:3 “2 to 3” “the ratio of girls to pupils is 2 to 3”

2nd Part:2nd Part:

READING ARITHMETICS

Addition (summation)

2+3=5 “2 plus 3 equals 5”“2 and 3 is 5”“2 and 3 add up to make 5”

“the sum of 2 and 3 is 5”

addends/ sum/resultsummands/ plus sign terms

Subtraction

7-4=3 “7 minus 4 equals 3”“7 take-away 4 leaves 3”“4 from 7 is 3”

minuend difference/resultsubtrahend minus sign (terms)

-4 “minus 4” or “negative 4”

Product (multiplication)

3×5=15 “3 times 5 is 15”“3 multiplied by 5 is 15”“3 by 5 equals 15

multiplicands/ product/result factors multiplication sign

2×5=10 “twice five is ten”

Division

6÷2=3 “6 divided by 2 is 3”“6 over 2 equals 3”

dividend quotient/result divisor division sign

7232 7232

1

1

7232

1

21

7232

1

1

70

21

7232

361

21

7232

61

70

21

7232

61

Division algorithm: 327÷2 quotientdivisor

dividend

remainder

Exponentiation

3 =9 “3 squared is 9”

3 =27 “3 cubed equals 27”

3 =81 “3 raised to 4 is equal to 81” “3 raised to the 4th power is 81” “3 raised to the power of 4 is 81”

base exponent/power/index

2

3

4

Roots

“the square root of 9 isof 9 is 3”

“the cubed root of 27 is 3”

“the 4th root of 81 is 3”

radicand index radical symbol

393273 3814

3rd Part:3rd Part:

READING GEOMETRY

a point

a straight line

a curved line

parallel straight lines

intersecting straight lines

perpendicular lines

90º

some geometric figures- perimeter

- area

triangle

quadrilateral

NOW YOU INVESTIGATE

“What is the name of the geometric figures, and the different types, in English?

(prepare a PowerPoint)