The Missing Dollar
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.
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
Student Exemplar 2
Student Exemplar 3