I'm smarter than you!

Teacher candidates from UWO read the story Smart Multiplication, explored ways of finding products in their heads, then scripted dialogues to be shared with elementary school students. One of the dialogues were used to make the song below, performed by grade 2-3 students.

Hey, Matt. I bet I’m smarter than you!
No way! No Way!
Then what’s 6x19
The answer is 114.
Well if that’s true, then what’s 99x8
The answer is Easy! It’s 792.

Wow! You are smarter.
How did…….. you do that?
You gotta change the problem into
something easier.
You know 100x8……….. is 800,
but that's too much………. So you subtract 8
To get 792.
I think I understand.

What’s 5x19?
Test me, Test me.
20x5………. is 100
So it must be 95.

Yeah! Now how do we decide
Who is smarter?

Two more dialogues developed by UWO teacher candidates:

Math without a calculator
Hey Mom.
Hey Jenny. What did you do in school today?
Today we learned an easy way to do math without a calculator.
Really, how?
For example, for the family reunion tomorrow you bought 13 bags of bun with 9 buns in each bag. How many buns do you think you have in total?
Hmm … wait, lat me grab my calculator.
No, Mom. Let me show you an easier way. See 9 is close to 10 and if you multiply 10 by 13 you get 130, but since we know there are less than 130 buns, how many do you think we have?
Well, since we added an extra bun per bag which is a total of 13 extra buns, we take away 13 from 130 to get … 117! I get it!
See, no need for a calculator.

Math at the train crossing
What did you learn in math today.
Aww shucks … a train!
Let’s count the train cars.
That’s so Kindregarten. At least give me a challenge!
Ummm …
Let’s figure out the total number of wheels … 47, 48, 49 – and that’s the caboose.
So there’s 8 wheels on each car and there are 49 cars altogether. So that’s 49 x 8.
Let’s see … 49, 9x8, … ummm … 72, ummm … carry the 7 …
No, no no, you’re doing it the hard way!
What do you mean?
Our group figured out that there are friendly numbers that can make multiplication easier.
So how would you do it?
Well I would make it 50 x 8 which is 400. Then subtract one group of 8 … 400 – 8 – 392, and THAT’S the easy way.
So you DID learn something in school today!
I guess …