Adding With Same Signs
Grade 8 math lesson on adding integers with the same sign. Students learn that adding two positive integers increases the value and adding two negative integers results in a more negative sum, and practice applying sign rules to integer addition.
Key Concepts
Property To find the sum of addends with the same sign: 1. Add the absolute values of the addends. 2. Take the sign of the addends.
Examples $( 7) + ( 6) = 13$ $(+11) + (+4) = +15$.
Explanation Think of it as teamwork! When two positives or two negatives get together, they join forces to make an even bigger number with the same sign. Everyone is on the same team here, so just add them up and keep their sign!
Common Questions
What happens when you add two positive integers?
Adding two positive integers gives a larger positive result. For example, 5 + 3 = 8. The sum is always positive and always larger than either addend.
What happens when you add two negative integers?
Adding two negative integers gives a larger negative result. For example, -5 + (-3) = -8. The sum is always negative, and its absolute value is larger than either addend individually.
How do you add integers with the same sign?
Add the absolute values of the two numbers, then apply the common sign to the result. For -7 + (-4): absolute values are 7 and 4, sum is 11, apply the negative sign: result is -11.
How does the number line show adding same-sign integers?
On a number line, adding a positive means moving right, and adding a negative means moving left. Adding two negatives means moving left twice, ending up further left (more negative) than where you started.