Practice Makes Perfect

Careful! English names for certain large numbers differ from those in other languages:

English Number

million 1,000,000

billion 1,000,000,000

trillion 1,000,000,000,000

When numbers are used in equations, there are specific mathematical terms to be used. In addi-

tion, numbers are combined by either the word plusor the word and: five plus three, ten and

nine.

In subtraction, the equation requires using the word minus(): ten minus four.

In multiplication, the equation requires using the word times(): six times three.

In division, the equation requires the phrase divided by(or /): twenty divided by five.

If an equation has an equal sign () in it, it is stated as equalsor is: two plus two equals four, six

minus three is three.

If a number is a decimal, the decimal is expressed by the word point: 6.5 is said as “six point five”;

10.7 is said as “ten point seven.”

The ordinal numbersare those that show a rank in a group or series. Most ordinals are formed by

adding -thto the end of the number: tenth, twentieth, sixty-seventh, hundredth, and so on. But five

ordinal numbers have special spellings which should be memorized:

1 first

2 second

3 third

5 fifth

12 twelfth

Some example sentences with ordinal numbers:

We have three daughters, but Denise was our first.

The second seating for dinner is at 8:30 P.M.

She was born on the twenty-fifth of June.

Dates are expressed in two ways: May fifthor the fifth of May. When giving a date as a number, it is

most common to give the month before the day: 9/11 September eleventh, 6/12 June

twelfth. In many other languages, the day precedes the month. This can cause confusion,

because to some people 6/12 means “the sixth of December.” To English speakers it most com-

monly means “June twelfth.” To avoid such confusion, it is wise to give dates in this form: June

12, 2005.

Ordinals are also used to express fractions other than^1 ⁄ 2 :

(^1) ⁄ 2 one-half (not an ordinal)
(^1) ⁄ 4 one-fourth (Note:One-fourth is sometimes expressed as “one-quarter” or “a
quarter.”)
(^1) ⁄ 3 one-third
(^3) ⁄ 10 three-tenths
(^14) ⁄ 25 fourteen twenty-fifths (Notice the plural formation of the ordinal when the
accompanying number is greater than one.)
Years that precede 2000 are expressed in two parts: 1850 is said as “eighteen fifty,”
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