Total: ¢
Question 9
Count the corner dots (vertices) of this shape:
Vertices count: 5 dots
Shape Name:
Question 10
Look at the bar graph. How many more students chose Soccer (12) than Tag (8)?
8
Tag
12
Soccer
5
Swings
A
3 students
B
4 students
C
5 students
Part 4
Maya baked 48 chocolate chip cookies and 27 oatmeal cookies. At her party, her friends ate 19 cookies. How many cookies does Maya have left?
Step 1: Add cookies together
Find how many cookies Maya baked in total:
48 + 27 =
Step 2: Subtract eaten cookies
Subtract the 19 cookies eaten from your Step 1 answer:
Step 1 - 19 =
Step 3: Complete the final sentence:
First, I added 48 and 27 to get cookies. Next, I subtracted 19 from that total. Maya has cookies left.
Grade 2 Math Showdown • Supported Version Page 2 of 2
Grade 2 Math Showdown • Teacher Resource Page 1 of 2
MATH SHOWDOWN ANSWER KEY Written Rubric & Diagnostics
Rubric
Problem: Maya baked 48 chocolate chip cookies and 27 oatmeal cookies. Her friends ate 19. How many are left?
Correct Answer: 56 cookies left. (48 + 27 = 75 total baked; 75 - 19 = 56 remaining).
| Score | Criteria | Standard Student Work Example |
|---|---|---|
| 4 pts | Perfect Execution: Correct answer (56). Shows all work clearly for addition and subtraction. Explains process accurately using complete sentences. | Work: 48+27=75, 75-19=56. |
| "First I added 48 and 27 to find all the cookies she made (75). Then I subtracted the 19 cookies they ate, which leaves 56." | ||
| 3 pts | Conceptual Understanding: Correct operations and strategy. Minor arithmetic calculation slip (e.g. 75-19 = 54) but explanation shows full logical path. | Work: 48+27=75, 75-19=54 (math error). |
| "I added the cookies to get 75. Then I subtracted 19 that they ate to get 54 cookies." | ||
| 2 pts | Partial Mastery: Correctly performs first step (48+27=75) but fails to complete second step, or shows steps but explanation is missing/unrelated. | Work: 48+27=75. (Stops here or subtracts incorrectly). |
| "Maya made 75 cookies in all." | ||
| 1 pt | Beginning Skills: Operations chosen are incorrect (e.g. subtracting oatmeal from choc chip), but student shows an attempt to organize numbers. | Work: 48 - 27 = 21. |
| "She has cookies left." |
1. Subtraction "Smaller-Minus-Larger" (Q4)
Misconception: On 62 - 38, students subtract the top smaller digit from the bottom larger digit (2 - 8 = 6) and write 36.
Intervention: Use place-value mats. Emphasize that "If you only have 2 ones, you cannot give away 8 ones. You must trade a ten rod for 10 ones!"
2. Forgetting the Regrouped Ten/Hundred (Q5)
Misconception: On 356 + 248, students write 6 + 8 = 14, write the 4, but forget to carry over and add the 1 to the tens column, resulting in 594.
Intervention: Have students box the carrying column physically on the paper. Use colored pencils to trace the regrouped "1" from the ones column to the tens column.
Grade 2 Math Showdown • Teacher Resource Page 2 of 2
