NUMBER SYSTEMPROPERTIES OF NUMBERS

Odd and Even numbers and

Negative and Positive numbers Round and Compare numbers

Sequences or Patterns in a set of numbers

VOCABULARY

If that digit is less than 5, do not change the "rounding digit" but

change all digits to the right of the "rounding digit" to zero.

http://www.youtube.com/watch?v=QutrbD8y-aY

Operation Result

Example(red is odd, blue is

even)Even + Even Even 2 + 4 = 6

Even + Odd Odd 6 + 3 = 9

Odd + Even Odd 5 + 12 = 17

Odd + Odd Even 3 + 5 = 8

Adding and SubtractingWhen you add (or subtract) odd or even numbers the results are:(The same thing happens if you subtract instead

of adding)

MultiplyingWhen you multiply odd or even numbers the results are always:

Operation ResultExample

(red is odd, blue is even)

Even × Even Even 4 × 8 = 32

Even × Odd Even 4 × 7 = 28

Odd × Even Even 5 × 8 = 40

Odd × Odd Odd 5 × 7 = 35