# 4.OA.A.3 Modeling Multi-Step Problems_Gaming Computer

## 4.OA.A.3 Modeling Multi-Step Problems with Unknown Quantity

**Evidence Statement 4.D.1-Solve multi-step contextual word problems with degree of difficulty appropriate to Grade 4, requiring application of knowledge and skills articulated in Type I Evidence Statements.**

### Gaming Computer

**Part A**

Ezra has $258 saved. He wants to buy a new Gaming Computer that costs $850.

He has a part-time job that pays $8 an hour. Each day Ezra works 6 hours.

- Write an equation to find the least number of shifts Ezra will have to work to afford the new Gaming Computer.
- Use a letter for the unknown value in your equation.

Write your equation and answer in the space provided.

**Part B**

Explain how you determined the number of days Ezra will have to work to afford the new computer

- How many shifts will Ezra need to work to afford the Gaming Computer? Explain your answer.

Enter your equation, answer, and explanation in the space provided.

### Student Copy

## Scoring Rubric

Score | Description |

2 |
Student response includes the following 2 elements.
The student provides a valid equation for finding the least number of days needed to afford the Gaming Computer Note: Equation should use a letter for the unknown value ($592.00 divided by 48= n) (division symbol can be used)
The student provides the correct number of shifts needed, ( 12 R 3 or 13 days) |

1 | Student response includes 1 of the 2 elements. |

0 | Student response is incorrect or invalid. |

Part B 1 | Reasoning Component = 1 pointThe student provides a valid explanation for how the number of shifts was determined, taking the remainder into consideration. Note: A valid explanation may include correct work with each step provided. Sample Student Response: $850.00- $258.00= $592.00 ( amount of money needed ) $8.00 x 6 = $48.00 ( amount of money earned each day) $592.00 ÷ $48.00= 12 R 3 ( amount of days to earn enough money) Final answer is 13 days because Ezra needs to work a 6 hour day. He can’t work only 3 hours to earn enough money to buy the computer |