Here Tracy walks around the room and ask students whether the question made sense for them. Students were unsure how to take the phrase "How much more does the sparkle apple pen cost?" and turn it into an operation.
TRACY LEWIS: Okay, I want you to take oh, six more minutes. Take six more minutes.
TRACY LEWIS: Okay, here's the question. This is stuff you already know, right? So you know what this is, right? You know what this is, right? So here's the question. How much MORE does the sparkle apple pen cost? Does this make sense?
TRACY LEWIS: No, it doesn't? Okay. So if I go to the store with money, and I want to buy something, how much MORE does it cost? I only have so much money to spend. Mm-mm. Put this over here. Show me how you know.
TRACY LEWIS: So we have two pens, right? She wants to buy a pen, but she only has so much money. She needs to know, Molly needs to know, she wants to buy a pen. How much more does this pen cost than that pen? Does that make sense?
TRACY LEWIS: Okay, so when you go to the store, sometimes don't you see the same thing for different prices?
TRACY LEWIS: So that's what this is. There are two pens, they cost two different amounts. How much more...do you think that means you're supposed to add it together?
TRACY LEWIS: Why? (student responds) But how much more does what cost?
STUDENT: The pen.
TRACY LEWIS: Are we buying both pens? Or are we only buying one? Does the problem say we're buying both pens?
TRACY LEWIS: Okay. So we want to buy AN apple pen. How many pens are we buying.
TRACY LEWIS: Okay, we're only going to buy one apple pen. But when you spend your money, don't you want to make sure you're getting what you want?
TRACY LEWIS: So if I want to spend, or buy an apple pen, I need to know how much MORE does this cost? How much more. So if this one costs, you tell me, this one cost how much?
TRACY LEWIS: 48 cents. So I've got some change in my pocket. What if I really want to buy this one?
TRACY LEWIS: I could buy both? How do I know if I have enough money? Yes. Oh. You want to add them together to see if I can buy both? What if I can only buy one?
STUDENT: Pick the one that you like?
TRACY LEWIS: Pick the one that I like? I like this one, but I don't know how much money I need. How much MORE money do I need to buy this one? So I have 48... oh! Don't mix my money up!
In this portion, students have access to manipulatives to revisit this problem. Several students took out money, and some students took out base 10 blocks. I gave them the option of using whatever tool they thought would help them. As a teacher, I was battling students' strong desire to buy both pens and challenging them on their misperception of the answer "buy both." Even with the manipulatives in front of one student showing the correct amounts for both pens, when I asked her how much more, she combined them all together.