# 2.NBT.A.1 Flawed Reasoning_Jasleen Swim Ribbons

## 3.C.4-7 Flawed Reasoning 2.NBT

The table below shows the number of ribbons a swim team earned during their swim season.

Ribbon Count

## Part A

Jasleen says the team won 619 because 3+2+1=6, and 4+6+9=19. Explain why she is wrong. Then write the total number of ribbons earned.

## Part B

Jasleen says the team won 25 less third place ribbons then first place ribbons because 3-1=2

and 9-4=5. .Explain why she is wrong. Then write how many less third place ribbons were earned than first place.

## Scoring Rubric Part A

Score 2 Student response includes the following 2 elements.

• Computation component = 1 point

o   The student provides the correct number of ribbons earned, 79 ribbons.

• Reasoning component = 1 point

o   The student explains that Jasleen did not use place value correctly.

• Notes:  If a computation mistake is made, credit cannot be given for the computation component, but 1 point can be given for a valid explanation.

Score 1 Student response include 1 of the above elements.

Score 0 Student response is incorrect or irrelevant.

## Scoring Rubric Part B

Score 2 Student response includes the following 2 elements.

•  Computation component = 1 point

o   The student correctly provides how many less third place ribbons were earned, 15 ribbons.

• Reasoning component = 1 point

o   The student explains that Jasleen did not use place value correctly.

• Notes:  If a computation mistake is made, credit cannot be given for the computation component, but 1 point can be given for a valid explanation.

Score 1 Student response include 1 of the above elements.

Score 0 Student response is incorrect or irrelevant.