The Missing Dollar


Curriculum Expectations

Number Sense 8m23 Evaluate expressions that involve integers, including expressions that contain brackets [...] using order of operations.


Transcript: These three stick men were having lunch in a restaurant. The bill came out to $30, so they each put in $10 (since $latex \$10 \times 3 = \$30$ total).

The cashier realizes that they've been overcharged $5, so he gives $5 back to the waitress to give to the men. But since $5 can't be divided equally, she decides to just give the men back $1 each, and keep $2 for herself.

So that means each man paid $latex \$10 - \$1 = \$9$.

All three men paid $latex 3 \times (10 - 1) = \$27$ in total.

Since the waitress kept $2, and the men paid $27, you get $latex 3 \times (10 - 1) + 2 = \$29$.

1. What happened to the extra dollar?


2. Students can use any type of manipulatives they like to solve the problem. Have a variety of manipulatives to choose from.


Student Exemplars

The following exemplars are all somewhere in a level 4, which as a percentage means something between 80% and 100%.

Here is the original Exit Ticket (evaluation) as a Word document: 2015-11-10 Chapter 1 Number Relationships The Missing Dollar Problem

Student Exemplar 1

Exemplar 1-1.pngExemplar 1-2.jpg

Student Exemplar 2

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Student Exemplar 3

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