Expanded Form Addition: Adding numbers by breaking them into tens and ones, then adding like place values separately
- Write both numbers in expanded form
- Add the tens together
- Add the ones together
- Combine the sums
- Write final answer in standard form
25 = 20 + 5
13 = 10 + 3
(20 + 5) + (10 + 3) = (20 + 10) + (5 + 3)
20 + 10 = 30
5 + 3 = 8
30 + 8 = 38
25 + 13 = 38
• Place Value Addition: Add tens to tens and ones to ones
• Expanded Form: Break numbers into tens and ones
• Verification: Check by adding directly: 25 + 13 = 38 ✓
34 = 30 + 4
25 = 20 + 5
(30 + 4) + (20 + 5) = (30 + 20) + (4 + 5)
30 + 20 = 50
4 + 5 = 9
50 + 9 = 59
34 + 25 = 59
• Place Value Addition: Add tens to tens and ones to ones
• Expanded Form: Break numbers into tens and ones
• Verification: Check by adding directly: 34 + 25 = 59 ✓
42 = 40 + 2
17 = 10 + 7
(40 + 2) + (10 + 7) = (40 + 10) + (2 + 7)
40 + 10 = 50
2 + 7 = 9
50 + 9 = 59
42 + 17 = 59
• Place Value Addition: Add tens to tens and ones to ones
• Expanded Form: Break numbers into tens and ones
• Verification: Check by adding directly: 42 + 17 = 59 ✓
56 = 50 + 6
23 = 20 + 3
(50 + 6) + (20 + 3) = (50 + 20) + (6 + 3)
50 + 20 = 70
6 + 3 = 9
70 + 9 = 79
56 + 23 = 79
• Place Value Addition: Add tens to tens and ones to ones
• Expanded Form: Break numbers into tens and ones
• Verification: Check by adding directly: 56 + 23 = 79 ✓
64 = 60 + 4
35 = 30 + 5
(60 + 4) + (30 + 5) = (60 + 30) + (4 + 5)
60 + 30 = 90
4 + 5 = 9
90 + 9 = 99
64 + 35 = 99
• Place Value Addition: Add tens to tens and ones to ones
• Expanded Form: Break numbers into tens and ones
• Verification: Check by adding directly: 64 + 35 = 99 ✓
Complete Guide to Expanded Form with Addition
This summary provides a comprehensive overview of expanded form addition, covering all essential concepts, methods, and practice strategies.
- Expanded Form: Writing a number as the sum of its place values (e.g., 25 = 20 + 5)
- Place Value: The value of a digit based on its position in a number
- Tens Place: The second digit from the right; represents groups of 10
- Ones Place: The rightmost digit; represents individual units
- Expanded Form Addition: Adding numbers by breaking them into tens and ones, then adding like place values separately
- Like Place Values: Adding tens with tens and ones with ones
- Place Value Rule: Each position has a specific value (ones, tens, hundreds, etc.)
- Tens Rule: Tens digit × 10 = tens value
- Ones Rule: Ones digit × 1 = ones value
- Addition Rule: Add like place values together (tens with tens, ones with ones)
- Verification Rule: Adding expanded parts gives the original number
- Expand Both Numbers: Write each number in expanded form (tens + ones)
- Group Like Values: Rearrange to group tens together and ones together
- Add Tens: Add all the tens values together
- Add Ones: Add all the ones values together
- Combine Results: Add the tens sum to the ones sum
- Verify: Check by adding original numbers directly
Simple Examples:
23 + 14: (20 + 3) + (10 + 4) = (20 + 10) + (3 + 4) = 30 + 7 = 37
15 + 22: (10 + 5) + (20 + 2) = (10 + 20) + (5 + 2) = 30 + 7 = 37
Intermediate Examples:
34 + 25: (30 + 4) + (20 + 5) = (30 + 20) + (4 + 5) = 50 + 9 = 59
46 + 13: (40 + 6) + (10 + 3) = (40 + 10) + (6 + 3) = 50 + 9 = 59
Advanced Examples:
57 + 32: (50 + 7) + (30 + 2) = (50 + 30) + (7 + 2) = 80 + 9 = 89
68 + 21: (60 + 8) + (20 + 1) = (60 + 20) + (8 + 1) = 80 + 9 = 89
- Always Expand First: Break both numbers into tens and ones before adding
- Group Together: Put all tens in one group and all ones in another
- Add Separately: Add tens to tens, then ones to ones
- Combine Carefully: Add the tens sum to the ones sum
- Verify Always: Check by adding original numbers directly
- Mixing Place Values: Adding tens to ones instead of like values
- Forgetting Expansion: Trying to add without breaking into place values
- Grouping Error: Not organizing tens and ones separately
- Combining Mistakes: Adding the wrong sums together
- Verification Neglect: Not checking the final answer
- "Tens with Tens, Ones with Ones": Always add like place values
- "Expand First": Break numbers into tens and ones before adding
- "Group and Add": Group like values, then add each group
- "Combine Last": Add the group totals together
- "Check Always": Verify by direct addition
- Expanded form addition helps understand place value relationships
- Adding like place values separately makes addition clearer
- Every two-digit number can be broken into tens and ones
- Verification builds confidence and prevents errors
- Practice with various numbers strengthens place value understanding