Hi, my name is Todd Vogtman. I teach third grade at Mount Savage Elementary School. Today
I'm going to model for you how to multiply by skip counting and also using a number line.
Okay, I'm going to read the problem to you now. A
dodgeball tournament has 12 teams.
Each team has five players. How many players are there in all?
Now as I read the problem I want to look for why is this a multiplication problem? I look for key words.
One key word in this problem that I see, that kind of triggers in my mind that it's multiplication would be the word each.
When you see the word each it kind of helps you to know that it's multiplication.
To solve the problem, I'm going to skip count by 5
twelve times.
5 ,10,
15, 20, 25,
30,
35, 40, 45, 50, 55, 60.
Then I'm going to write an equation to match the story.
12
times 5
will equal the answer that I previously showed you of sixty total players.
Now I'm going to model the same exact problem but instead of skip counting
I'm going to use an open number line in order to find our answer.
Now I'm going to model the same problem except this time use an open number line.
Here I've created an open number line from 0 to 65. I
am now going to use the open number line
to hop by 5 twelve times.
1,
2,
3,
4,
5,
6,
7, 8,
9,
10, 11, 12.
As you can see I land on 60.
I can now write an equation to match the story.
12
times 5
again equals 60 total players.
