Strategy: Zero times any number is ALWAYS zero. This is called the zero property of multiplication. I used this video from youtube.com to help explain to my kids this principle.


To help my kids remember this rule, I showed them this picture from Resources to the Rescue (which made them chuckle). They easily understand that Super Zero always wins and that any number multiplied by zero is always zero.

Photo from teacherspayteachers.com

We then practice multiplying by zero. I ask them to reply promptly as they can when I ask multiplication questions. I began with small numbers (2 x 0 =, 5 x 0 =, 7 x 0 =). When they were able to answer, I asked them again this time with bigger numbers (1000 x 0 =, 1,000,000 x 0 =, etc). 

I also asked them to answer this worksheet. I explained that Zero Monster is always hungry. He eats any number multiplied by him. That's why like Super Zero, he always wins. After answering, my 7-year daughter gave to me her worksheet, saying that Zero Monster is already full :)

Photo from free-math-handwriting-and-reading-worksheets.com