N

negative number

A number less than zero; a number to the left of zero on a horizontal number line.

pages 243–245, 251, 272

number line

A line where numbers are marked at intervals.

pages 74–75, 76–79, 80–81, 82–85, 87–88, 102–103, 105–108, 117, 126–128, 129–135, 210–215, 243–247, 338, 370, 388–389, 396–398, 458–459, 460

number sentence

An equation or inequality with numbers. For example, 3 × 2 + 5 = 10 + 1 and 2 < 3 + 1.

pages 65–68, 69–73, 78–79, 80–81, 90–99, 101–103, 113–115, 131–135, 236–237, 301–302, 397–398, 446–448

numerator

The number written above the line in a fraction. For example, 3 is the numerator in the fraction . (See also denominator.)

pages 58–63, 64–68, 84–85, 91, 211, 213–214, 218–219, 461–462

numerical expression

A combination of numbers and operations, e.g., 5 + 8 ÷ 4.

page 344

numerical variable

Variables with values that are numbers. (See also variable and value.)

pages 4, 16, 36, 40, 44, 46, 48, 51