3-7-11 Adding & subtracting negative numbers [K-119 박정민]

[이상수]

3. Pre-algebra 기초 대수학

7. Negative numbers and coordinate plane

Intro to subtracting negative numbers

3-7-11 Adding & subtracting negative numbers

https://www.khanacademy.org/math/pre-algebra/pre-algebra-negative-numbers/pre-algebra-sub-neg-intro/v/adding-and-subtracting-negative-number-examples