Why is a minus times a minus a plus? Explaining it to first-year junior high students who struggle with positive and negative numbers using a number line

I have been asked by parents of first-year junior high students who were unable to answer well when their children asked, ...

On Positive and Negative Numbers and Vectors | Foreshadowing from Junior High to High School Mathematics â‘£

Introduction"Actually, we've been doing this since the first year of junior high."This happened when I was explaining ...