Elliot drew this model to solve the problem −3+4 but then realized he made a mistake. (a) What addition problem is represented by Elliot’s model?
(b) Draw a correct model for the addition problem −3+4.
(c) Explain what each part of your model represents and use the model to find the sum.

The expression shown can be used to calculate the amount of money in dollars a grocery store customer should receive in change when paying with $100.
100−(28+3+2(3)+3(5)+3)
(a) What part of the equation represents the amount of money that is spent? Justify your answer. (b) What is the total amount spent?
(c) What amount of change should the customer receive?

3. Four points are labeled on this number line.
(a) What is the value of each point on the number line? (b) Which point represents the value of −2 1 ?
2
(c) Which point represents the value of 2 1 ? 2
(d) Explain your observations when comparing the answers of parts (b) and (c).