2nd Grade Subtracting Within 100 Test Solutions and Scoring (PDF)
This subtract within 100 test answers for 2nd Grade covers subtracting within 100 (Common Core 2.NBT.B.5, 2.NBT.B.9), with a free PDF to print.
Grade 2 · Common Core State Standards: 2.NBT.B.5, 2.NBT.B.9
Subtract within 100 test answers: worked solutions
Question 1 – Tens and ones [2 pts]
- \(87 – 40 = 47\)
- \(56 – 23 = 33\)
Scoring: 1 point for each correct difference.
Question 2 – Blocks [2 pts]
- \(62 – 38\)
- Trade 1 ten: 5 tens and 12 ones. \(12 – 8 = 4\) and \(5 – 3 = 2\). The difference is \(24\).
Scoring: 1 point for the correct sentence, 1 point for 24.
Question 3 – Subtract with trading [3 pts]
- 6 tens and 14 ones: \(14 – 8 = 6\), \(6 – 3 = 3\). 36
- 4 tens and 10 ones: \(10 – 7 = 3\), \(4 – 2 = 2\). 23
- 8 tens and 11 ones: \(11 – 5 = 6\), \(8 – 6 = 2\). 26
Scoring: 1 point for each correct difference.
Question 4 – Number line [2 pts]
- \(82 – 48\)
- Count up: 48 to 50 is 2, 50 to 80 is 30, 80 to 82 is 2. \(2 + 30 + 2 = 34\). The distance is \(34\).
Scoring: 1 point for 82 – 48, 1 point for 34.
Question 5 – Missing part [2 pts]
\(77 – 29\): 6 tens and 17 ones. \(17 – 9 = 8\) and \(6 – 2 = 4\).
The missing part is \(48\).
Scoring: 1 point for 77 – 29, 1 point for 48.
Question 6 – Check Zoe's answer [2 pts]
Check: \(55 + 39 = 94\), not 84. So Zoe is not correct.
\(84 – 39\): 7 tens and 14 ones. \(14 – 9 = 5\) and \(7 – 3 = 4\). The correct difference is \(45\).
Scoring: 1 point for the addition check, 1 point for 45.
Question 7 – Two jumps back [2 pts]
Split 28 into 20 and 8: \(63 – 20 = 43\), then \(43 – 8 = 35\).
The answer is \(35\).
Scoring: 1 point for splitting 28 into two parts that work, 1 point for 35.
Question 8 – Bead box [2 pts]
\(92 – 47\): 8 tens and 12 ones. \(12 – 7 = 5\) and \(8 – 4 = 4\).
Mei has 45 beads left.
Scoring: 1 point for the correct subtraction, 1 point for 45 beads.
Question 9 – Trading cards [3 pts]
Step 1: \(80 – 26\): 7 tens and 10 ones. \(10 – 6 = 4\) and \(7 – 2 = 5\), so 54.
Step 2: \(54 – 17\): 4 tens and 14 ones. \(14 – 7 = 7\) and \(4 – 1 = 3\), so 37.
Noah has 37 cards left.
Scoring: 1 point for each correct subtraction, 1 point for the final answer.
Total score
20 points
Key facts behind this subtract within 100 test answers
- Trade 1 ten for 10 ones when the ones on top are too few.
- The difference is the answer to a subtraction problem.
- Counting back and counting up both find the same difference.
- Check subtraction with addition: difference + smaller number = whole.
- A bar model shows a whole and two parts.
How to use this subtract within 100 test answers
Score your test with the point values shown for each question. Then read the worked solution of every question where you lost points and note the method to review.
All Grade 2 chapters: Grade 2 math.
