Solved Exercises on Addition/Subtraction Worksheet in Grade 2

Master addition and subtraction within 100: practice problems, skill building, and comprehensive exercises through these 5 detailed worksheet-style exercises.

Solution: Exercises 1 to 3
1 Basic Addition Facts
Exercise 1
Complete the addition facts:
6 + 7 = ?
8 + 5 = ?
9 + 4 = ?
7 + 6 = ?
Definition:

Addition Facts: Basic addition combinations that should be memorized

Addition Fact Strategies:
  1. Use counting on for small numbers
  2. Memorize doubles facts first
  3. Learn facts that make 10
  4. Use known facts to find new ones
6 + 7 = 13
8 + 5 = 13
9 + 4 = 13
7 + 6 = 13
Step 1: 6 + 7

Start with 6, count 7 more: 7, 8, 9, 10, 11, 12, 13

Step 2: 8 + 5

Start with 8, count 5 more: 9, 10, 11, 12, 13

Step 3: 9 + 4

Start with 9, count 4 more: 10, 11, 12, 13

Step 4: 7 + 6

Use commutative property: 7 + 6 = 6 + 7 = 13

All equal 13
Final answer:

6 + 7 = 13, 8 + 5 = 13, 9 + 4 = 13, 7 + 6 = 13

Applied rules:

• Commutative Property: Order doesn't matter in addition

• Counting Strategy: Count on from the larger number

• Pattern Recognition: Notice that different pairs can equal the same sum

Addition Facts Practice
Name: ___________ Date: ___________
6 + 7 = ___
8 + 5 = ___
9 + 4 = ___
7 + 6 = ___
5 + 8 = ___
4 + 9 = ___
3 + 10 = ___
10 + 3 = ___
2 Basic Subtraction Facts
Exercise 2
Complete the subtraction facts:
15 - 7 = ?
12 - 5 = ?
18 - 9 = ?
14 - 6 = ?
Definition:

Subtraction Facts: Basic subtraction combinations that should be memorized

15 - 7 = 8
12 - 5 = 7
18 - 9 = 9
14 - 6 = 8
Step 1: 15 - 7

Think: 7 + ? = 15. We know 7 + 8 = 15, so 15 - 7 = 8

Step 2: 12 - 5

Count back from 12: 11, 10, 9, 8, 7. So 12 - 5 = 7

Step 3: 18 - 9

This is a doubles fact: 9 + 9 = 18, so 18 - 9 = 9

Step 4: 14 - 6

Think: 6 + ? = 14. We know 6 + 8 = 14, so 14 - 6 = 8

Results: 8, 7, 9, 8
Final answer:

15 - 7 = 8, 12 - 5 = 7, 18 - 9 = 9, 14 - 6 = 8

Applied rules:

• Inverse Relationship: Subtraction is the opposite of addition

• Counting Back: Count backwards from the larger number

• Fact Families: Use addition facts to solve subtraction

Subtraction Facts Practice
Name: ___________ Date: ___________
15 - 7 = ___
12 - 5 = ___
18 - 9 = ___
14 - 6 = ___
16 - 8 = ___
13 - 4 = ___
11 - 3 = ___
17 - 9 = ___
3 Column Addition
Exercise 3
Solve using column addition:
47
+25
___

38
+16
___
Definition:

Column Addition: Adding numbers vertically by place value

47
+25
___
72
38
+16
___
54
Step 1: Align numbers by place value

Line up the ones and tens columns properly

Step 2: Add the ones column first

For 47 + 25: 7 + 5 = 12 ones

Step 3: Regroup if necessary

12 ones = 1 ten and 2 ones. Write 2 in ones, carry 1 to tens

Step 4: Add the tens column

4 + 2 + 1 (carried) = 7 tens

Step 5: Write the final answer

7 tens and 2 ones = 72

47 + 25 = 72
Final answer:

47 + 25 = 72 and 38 + 16 = 54

Applied rules:

• Place Value: Add digits in the same place value columns

• Regrouping: When ones exceed 9, carry to tens column

• Sequential Order: Add ones first, then tens

Column Addition Practice
Name: ___________ Date: ___________
47
+25
___
38
+16
___
53
+29
___
64
+18
___
Rules and methods, laws,...
a + b = c
Addition Formula
Commutative
a + b = b + a
Order doesn't matter
Associative
(a + b) + c = a + (b + c)
Grouping doesn't matter
Identity
a + 0 = a
Adding zero doesn't change
Key definitions:

Worksheet: A structured set of practice problems

Addition: Combining quantities to find a total

Subtraction: Finding the difference or removing a quantity

Place Value: The value of a digit based on its position

Worksheet Completion Strategy:
  1. Read Instructions: Understand what is expected
  2. Survey Problems: Look for patterns or difficulty levels
  3. Start Easy: Begin with familiar problems to build confidence
  4. Show Work: Write down steps even for simple problems
  5. Check Answers: Review completed problems
Tip 1: Practice basic facts daily until they become automatic.
Tip 2: Use manipulatives like counters or base-ten blocks for hands-on practice.
Tip 3: Always line up numbers correctly in column addition/subtraction.
Solution: Exercises 4 to 5
4 Column Subtraction
Exercise 4
Solve using column subtraction:
53
-27
___

62
-35
___
Definition:

Column Subtraction: Subtracting numbers vertically by place value

53
-27
___
26
62
-35
___
27
Step 1: Align numbers by place value

Line up the ones and tens columns properly

Step 2: Check if borrowing is needed

In 53 - 27, we need to subtract 7 from 3 in the ones column

Step 3: Borrow from tens column

53 becomes 4 tens and 13 ones (53 = 40 + 13)

Step 4: Subtract the ones column

13 - 7 = 6 ones

Step 5: Subtract the tens column

4 - 2 = 2 tens

26
Final answer:

53 - 27 = 26 and 62 - 35 = 27

Applied rules:

• Place Value: Subtract digits in the same place value columns

• Borrowing: When top digit is smaller, borrow from higher place

• Verification: Check by adding the answer to the subtracted number

5 Mixed Operations
Exercise 5
Complete the mixed operations:
24 + 15 - 8 = ?
45 - 12 + 9 = ?
37 + 14 - 21 = ?
56 - 23 + 17 = ?
Definition:

Mixed Operations: Problems with both addition and subtraction

24 + 15 - 8 = 31
45 - 12 + 9 = 42
37 + 14 - 21 = 30
56 - 23 + 17 = 50
Step 1: Follow order of operations (left to right)

For 24 + 15 - 8: First add 24 + 15 = 39

Step 2: Continue with next operation

Then subtract: 39 - 8 = 31

Step 3: Repeat for other problems

Process each problem in the same sequential manner

Step 4: Verify answers when possible

Double-check calculations for accuracy

31, 42, 30, 50
Final answer:

24 + 15 - 8 = 31, 45 - 12 + 9 = 42, 37 + 14 - 21 = 30, 56 - 23 + 17 = 50

Applied rules:

• Left-to-Right: Perform operations in order from left to right

• Sequential Processing: One operation at a time

• Verification: Check that each step is calculated correctly

Add list of laws, methods, rules, definitions, expressions,.... Generate well SEO title for this section
a + b - c = d
Mixed Operations
Key definitions:

Addition: Combining two or more numbers to get a total

Subtraction: Taking away one number from another

Place Value: The value of a digit based on its position (ones, tens, hundreds)

Regrouping: Moving from one place value to another (carrying/borrowing)

Addition/Subtraction Methods:
  1. Counting On: Start with larger number and count up
  2. Make Ten: Use 10 as a benchmark for easier calculation
  3. Column Method: Align by place value and calculate by column
  4. Fact Families: Use related addition/subtraction facts
  5. Compensation: Adjust numbers to make calculations easier
Tip 1: Practice with flashcards to build automaticity with basic facts.
Tip 2: Use a number line to visualize addition and subtraction.
Tip 3: Always check subtraction by adding your answer to the smaller number.
Tip 4: Draw pictures or use objects when you're stuck on a problem.
Common errors: Misaligning columns, forgetting to carry/borrow, misreading signs.
Practice recommendations: Daily worksheets, timed drills, word problems.
Essential Rules:

• Commutative Property: a + b = b + a

• Associative Property: (a + b) + c = a + (b + c)

• Identity Property: a + 0 = a

• Inverse Operations: Addition and subtraction undo each other

Exercise with Visualization: Practice Progress
Exercise 6: Skills Development
Track your improvement: Week 1: 15/20 correct, Week 2: 18/20, Week 3: 19/20

Analysis: Consistent practice leads to improvement in addition/subtraction skills.

  • Week 1: 75% accuracy
  • Week 2: 90% accuracy
  • Week 3: 95% accuracy

Questions & Answers

Question: I make mistakes when I have to carry in addition. How can I remember to do it?

Answer: Here are strategies to remember carrying in addition:

  • Circle the carry: When you get 10 or more in a column, circle the number to carry
  • Say it out loud: "I have 12 ones, so I write down 2 and carry 1 ten"
  • Write small: Write the carried number in a smaller size above the next column
  • Check immediately: After carrying, add the carried number to the next column right away

Example: In 27 + 15, when adding 7 + 5 = 12, write 2 in the ones place and put a small 1 above the tens column, then add 1 + 2 + 1 = 4 in the tens place.

Practice with smaller numbers first until carrying becomes natural!

Question: Why do I need to line up numbers in column addition? Can't I just add them any way?

Answer: Lining up numbers by place value is crucial for accurate addition:

  • Place value system: Each position represents different values (ones, tens, hundreds)
  • Accurate calculation: Ones must be added to ones, tens to tens
  • Error prevention: Misalignment causes wrong answers
  • Future math: This skill is essential for more complex operations

Example: If you add 23 + 45 without lining up:
23
+45
___
Would give wrong results. But lined up:
23
+45
___
68 (correct!)

Always align the rightmost digits (ones place) when adding!

Question: How do I know if my subtraction answer is right? I often get the wrong number.

Answer: Here's how to check your subtraction answers:

  • Add back: Take your answer and add it to the number you subtracted
  • Should equal original: The sum should equal the first number in your subtraction
  • Example: For 15 - 7 = 8, check: 8 + 7 = 15 ✓
  • Estimate first: Before calculating, estimate to see if your answer is reasonable

Another method is to count up from your answer to the original number:

If 15 - 7 = 8, count from 8: 9, 10, 11, 12, 13, 14, 15. That's 7 numbers, so it's correct!

Checking your work takes extra time but prevents mistakes!