## Tuesday, June 16, 2009

### Reading out numbers in English

1 + 4 = 5 : One plus four equals(is) five

Subtractions
12 - 4 = 8 : Twelve minus four equals(is) eight.
12 - 4 = 8 : Four from twelve equals(is) eight.

Multiplications
2 × 3 = 6 : Two times three equals(is) six.

Divisions
20 ÷ 4 = 5 : Twenty divided by four equals(is) five.

10^2 = 100 : 10 squared equals(is) one hundred.
10^3 = 1,000 : 10 cubed equals(is) one thousand.
10^3 = 1,000 : 10 to the third power equals(is) one thousand.
10^4 = 10,000 : 10 to the fourth power equals(is) ten thousand.
2^4 = 32 : Two to the fourth power equals(is) thirty-two.

Decimals
A decimal is a fraction that is written in the form of a dot followed by one or more numbers which represent tenths, hundredths, and so on: for example .5, .51, .517.

π = 3.14 : Pi equals three point one four
15.93 : fifteen point nine three
0.8473 : zero point eight four seven three, point eight four seven three
0.034 : zero point zero three four, point zero(oh) three four

Fractions
A fraction is a number that can be expressed as a proportion of two whole numbers. For example, 1/2 and 1/3 are both fractions.

numerator, denominator
A numeraror is the number on top of fraction. For example, in 3/4, 3 is the numerator and 4 is the denominator.
A common denominator is a number which can be divided exactly by all the denominators in a group of fractions.

1/8 : one-eighth, one over eight
2/3 : two-thirds
1/4 : one-fourth, one-quarter
1/2 : one-half, half
3/4 : three-fourths, three-quarters
4/7 : four-sevenths, four over seven

1/3 + 1/4 = 4/12 + 3/12 = 7/12
One-third plus one-fourth is the same as four-twelfths plus three-twelfths, and that equals seven-twelfths.

Big number
100 : hundred 1,000 : thousand 10,000 : ten thousand 100,000 : one hundren thousand
1,000,000 : one million
1,000,000,000 : one billion
1,000,000,000,000 : one trillion

Years
B.C 340 : three hundred forty B.C.
Year 890 : eight hundred ninety
Year 1880 : eighteen eighty
Year 1953 : nineteen fifty three
Year 1988 : nineteen eighty eight
Year 2000 : two thousand
Year 2002 : two thousand two, twenty oh two
Year 2010 : two thousand ten, twenty ten
Year 2100 : two thousand one hundred, twenty one hundred