2.1 Adding Rational Numbers

2.1 – Adding Rational #s Goals / “I can…” Add rational numbers using models and rules Apply addition

2.1 – Adding Rational #s What is your identity? What is the inverse of something?

2.1 – Adding Rational #s PROPERTY – Identity Property of Addition For all real numbers, n + 0 = n and 0 + n = n PROPERTY – Inverse Property of Addition For all real numbers, n + (-n) = 0 additive inverse

2.1 – Adding Rational #s RULE – Adding Numbers 1. When adding number with the same sign, the sum has the same sign. 2. When adding number with different signs, subtract the numbers and keep the sign from the larger absolute value.

2.1 – Adding Rational #s Example 12 + (-23) = (-32) =

2.1 – Adding Rational #s Example The water level in a lake rose 6 inches and then fell 11 inches. Write a statement to show the total level change.

2.1 – Adding Rational #s How would you read the expression –n? It should be read as the opposite of n, because what happens if n is negative.

2.1 – Adding Rational #s Evaluate: -x + 23 if x = (-y) if y = 17

2.1 – Adding Rational #s Matrices A Matrix is a collection of number in rows and columns. Each number is called an Element. A matrix is defined by the number of rows by columns.

2.1 – Adding Rational #s is a 3 x 4 matrix. 3 rows x 4 columns.

2.1 – Adding Rational #s Example 6: