Hello, my name is Sarah Cessna, I am a first-grade teacher at George's Creek Elementary School. Today
I am going to model subtraction within twenty using a number line.
My word problem today is
Adrienne had sixteen Skittles. She ate 9. How many Skittles
does Adrienne have left? I'm going to circle sixteen and
nine
because those are the numbers that I'm going to put in my equation. And left
because left is a magic word that means subtraction. So when I write my equation, I
write sixteen
minus nine equals.
I
find sixteen on the number line.
I'm
going to move backwards nine.
One, two, three, four, five,
six, seven, eight, nine. I land on seven.
Sixteen minus nine equals seven. The difference is 7 seven.
