Math Word List 5Math Word List 5

Obtuse AngleObtuse Angle• An obtuse angle is more than 90° but

less than 180°

In other words, it is between a right angle and a straight angle.

Right AngleRight Angle• A right angle is an angle which is

equal to 90°, one quarter ( 1 /4) of a full revolution or turn.

Straight AngleStraight Angle• A straight angle changes the

direction to point the opposite way. It looks like a straight line.

It measures 180° (half a revolution, or two right angles)

DecimalDecimal• Based on 10

Example: the numbers we use in everyday life are decimal numbers, because there are 10 of them (0,1,2,3,4,5,6,7,8 and 9).

Often "decimal number" is also used to mean a number that uses a decimal point followed by digits as a way of showing values less than one.

Example: 1.9 is a decimal number (one and nine tenths)

Greatest Common FactorGreatest Common Factor• The highest number that divides exactly into two

or more numbers.

If you find all the factors of two or more numbers, and you find some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.

Abbreviated "GCF". Also called "Highest Common Factor

6 = 1, 2, 3, 630 = 1, 2, 3, 5, 6, 10, 15, 30GCF = 6

Simplest FormSimplest Form• Making a fraction as small as

possible

• To do this you divide by the GCF

• Also called reducing a fraction or writing it in lowest terms.

Reducing a FractionReducing a Fraction

• Making a fraction as small as possible

• To do this you divide by the GCF

• Also called simplest form or writing it in lowest terms.

Greater ThanGreater Than• Bigger.

The symbol > means greater than (the symbol < means less than).

Example: 5 > 3 shows that 5 is greater than 3

Less ThanLess Than• Smaller.

There is a special symbol used to show that one number is smaller than another

The symbol < means less than (the symbol > means greater than).

Example: 4 < 9 shows that 4 is less than 9

Simplify a fractionSimplify a fraction• Making a fraction as small as

possible

• To do this you divide by the GCF

• Also called reducing a fraction or writing it in lowest terms.

Lowest TermsLowest Terms• Making a fraction as small as

possible

• To do this you divide by the GCF

• Also called reducing a fraction or writing it in lowest terms.

CommonCommon• The same

Factors of 12 = 1, 2, 3, 4, 6, 12 18 = 1, 2, 3, 6, 9, 18

They have the factors 1,2,3, and 6 in

common

Least Common MultipleLeast Common Multiple• The smallest number that is a multiple of two or

more numbers.

Example: the Least Common Multiple of 3 and 5 is 15, because 15 is a multiple of 3 and also a multiple of 5. Other common multiples include 30 and 45, etc, but they are not the smallest (least).

(Also called Lowest Common Multiple)

NumeratorNumerator• The top number in a fraction.

Shows how many parts we have.

EquivalentEquivalent• Having the same value.

Example 0.5 is equivalent to ½