Adding Two Negatives
Part of the Numbers & Operations section of Coddy's Pre-Algebra journey. Lesson 18 of 60.
What is -5 + (-3)? Start at -5 on the number line. Adding a negative number walks you to the left, so three more steps left lands on -8. The sizes combine, 5 and 3 make 8, and the answer keeps the minus sign.
From -5, three steps left lands on -8.
Why does the sum stay negative? Think of money owed. Owing 5 dollars and then owing 3 more means you owe 8. Nothing positive arrived to pull you back toward zero, so you only moved further below it.
Adding a negative is the same as taking away its size: -5 + (-3) and -5 - 3 both land on -8. Books and calculators often write it the short way, -5 - 3, so read that as two negative numbers being combined.
Challenge
Work out -9 + (-14). Type the result.
Try it yourself
Simplify the expression
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Numbers & Operations
1Working on the Board
Your First AnswerType the Next LineOne Line at a TimeDots and BarsFriendly ProductsRecap: Board Work4Adding Integers
Adding Two NegativesDifferent SignsZero PairsAdding Several IntegersRecap: Adding Integers2Order of Operations
Multiply Before AddingLeft to RightParentheses FirstBrackets Inside BracketsThe Fraction Bar GroupsRecap: Order of Operations5Subtracting Integers
Add the OppositeSubtracting a NegativePlus and Minus in a RowDistance Between NumbersRecap: Subtracting Integers