Algebra I Recipe: Numbers and Number Operations
A. Definitions
1. whole numbers - are positive numbers beginning with zero such as 0, 1, 2, 3, 4, . . .
2. fraction - is a part of a whole number written with a fraction bar where the top number is the numerator and the bottom number is the denominator.
• Given the fraction 3/5, 3 is the numerator and 5 is the denominator.
• To change a fraction to a decimal, divide the denominator into the numerator.
for example: ½ = 1 ÷ 2 = 0.5
3. decimal - is a part of a whole number written with a decimal point where the place values to the right of the decimal are: . (tenths) (hundredths) (thousandths) (ten thousandths) etc.
• To round a number to a particular place value, look at the number to the immediate right of the place value and if it is 5 or more round up one, but if it is 4 or less leave at the same value.
Examples:
 2.4372 rounded to the nearest 100th
 0.5612 rounded to the nearest 1000th

1. To change a decimal to a percent, move the decimal two places to the right.
Examples:
 0.5
 0.467

1. percent - some part out of 100.
1. To change a percent to a fraction, put the number over 100 and then reduce.
Example:
 50%

1. To change a percent to a decimal, move the decimal two places left.
Examples:
 65%
 41.8%

1. numerical expression - an expression with numbers and operations such as [8 - 3(2)] ÷ 6
2. grouping symbols
• parentheses ( )
• brackets [ ]
• braces { }
3. evaluate - means to find the value of the expression.
• Perform operations inside parentheses.
• Perform all multiplication and division as they appear from left to right.
• Perform all addition and subtraction as they appear from left to right.
4. perimeter - is the distance around an object.
• Find the perimeter by adding the lengths of each side of the object together.
5. area of a rectangle - is the space inside the rectangle given in square units.
B. The 4 Basic Operations and Their Symbols
1. Sum means to add: use +
2. Difference means to subtract: use -
3. Product means to multiply: use ( )( ), ·, 2( ), 5x
4. Quotient means to divide: use ÷ or the fraction bar (¾)
Practice Problems

G Redden

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