School and Family
Unit 21 Add, Subtract, Multiply and Divide
Hello there, Terry. How are you doing?
Not too well. I'm really having trouble figuring out this arithmetic assignment.
I can add and subtract pretty well, but without a calculator, it's difficult for me to multiply and divide.
Hey, Olaf, I heard that you're excellent in math.
My technique is that I try to imagine pictures in my mind, so the numbers aren't just figures on a page, but something I can apply to real life.
One way I do this is to imagine the numbers as if they were money.
For example, if the equation is 753 minus 236, I think about $7.53 minus $2.36.
It's $5.17, or 517. Easy!
Wow, that does seem easier for adding and subtracting, but how do you apply this technique to multiplying and dividing?
Okay, suppose the equation is 200 times 30. 30 is 3 groups of 10.
So, first I imagine 10 groups of people standing in a large field.
Next to each group is a sign with the number 200 on it.
At the front of the field is a huge sign with the number 2,000 on it, because 200 times 10 equals 2,000, right?
But the problem requires 200 times 10 three times, so I just add two more fields of people to my picture with two more signs that say 2,000.
Now I have 2,000 times 3. The answer is 6,000!