1. จงเขียนการคูณจำนวนต่อไปนี้ในรูปการบวกแล้วหาผลลัพธ์

        1)      2 3 = ................................................................ = ................................................................

        2)      3  2 = ................................................................ = ................................................................

        3)      5  7 = ................................................................ = ................................................................

        4)      7  5 = ................................................................ = ................................................................

2. จากข้อ 1. การคูณจำนวนเต็มมีสมบัติการสลับที่การคูณหรือไม่ .....................................................

        เช่น   2  3 = 3  2

                5  7 = 7  5

3. จงเขียนการคูณจำนวนต่อไปนี้ในรูปการบวกแล้วหาผลลัพธ์

        1)      2  (-3) = ............................................................... = ................................................................

        2)      3  (-2) = ............................................................... = ................................................................

        3)      3  (-5) = ............................................................... = ................................................................

        4)      5  (-3) = ............................................................... = ................................................................

4. จงเขียนการคูณจำนวนต่อไปนี้ โดยใช้สมบัติการสลับที่การคูณ แล้วเขียนในรูปการบวกพร้อมทั้งหา

     ผลลัพธ์

        1)      (-3)  2 = ............................................................... = ................................................................

        2)      (-2)  3 = ............................................................... = ................................................................

        3)      (-5)  3 = ............................................................... = ................................................................

        4)      (-3)  5 = ............................................................... = ................................................................

5. จากข้อ 3. และข้อ 4. จะได้ว่า

        1)      2  (-3) = ............................................................... = ................................................................

        2)      3  (-2) = ............................................................... = ................................................................

        3)      3  (-5) = ............................................................... = ................................................................

        4)      5  (-3) = ............................................................... = ................................................................