I often work with international Schools where the teachers commit to two-three years and then move on to other schools and other countries. I was surprised by an email this week from a former 3rd-grade teacher I worked with at a school in China. She is now teaching in Malaysia.

Hi Cassy, I’ve moved on…but all that bar model training is serving me well at the math PD at my new school!

She included this image:

- Can you write a word problem for this bar model and the calculations?
- What grade level might this be from?
- What do you notice about the manipuative used?
- What questions can we ask based on the model given?

Blake works at the pizza shop downtown. When he sells a pizza, he always cuts the pizza into 8 slices. One slice is enough to feed one person. All of his and George’s friends buy pizza from Blake’s pizza shop.

George is having a party, but cannot afford to buy all of the pizzas to feed his guests so he asks his friends to bring some pizzas. Since Blake is his best friend, he only asks Blake to bring one pizza. Ryan is his second best friend so he asks him to bring double the amount of pizzas as Blake. Celia didn’t bring anything to the last party so George asks her to bring four times the amount as Ryan to make up for the difference.

George was able to afford three times the amount of pizzas that Celia is bringing and with that, there would be just enough to feed the guests coming to the party. How many people can be fed with the pizzas that will be at the party?

Third grade level / Maybe early fourth.

Manipulatives: Each square = 8. Lends to visual processing of complex word problems.

Too many questions… not enough time.

At least 280 people because each guest can eat at least 1 slice each.

1 pizza=8 slices.

Blake brings 1 pizza

Ryan brings 2 pizzas (double what Blake is bringing)

Celia brings 8 pizzas (4 times what Ryan is bringing)

George brings 24 pizzas (3 times what Celia is bringing)

35 pizzas multiplied by 8 slices each= 280 pieces