Show your work using place value
Adding 10: When adding 10 to a single digit, the tens place increases by 1
- Recognize that 10 has 1 ten and 0 ones
- Add the ones place to the single digit
- The tens place stays 1
- Combine to form the answer
10 = 1 ten, 4 = 4 ones
1 ten + 4 ones = 14
10 + 4 = 14
10 + 4 = 14
• Place Value Rule: Adding 10 increases the tens place by 1
• Ones Place: The single digit moves to the ones place
• Number Pattern: 10 + n = 1n (where n is the single digit)
Break down using make 10 strategy
Make 10 Strategy: Break apart one number to combine with the other to make 10
From 8, we need 2 more to make 10 (8 + 2 = 10)
5 = 2 + 3 (the 2 goes with 8 to make 10, leaving 3)
10 + 3 = 13
8 + 5 = 13
• Make 10 Rule: Look for combinations that make 10
• Decomposition: Break numbers into parts
• Compensation: Adjust and balance the equation
Use mental math and place value
Mental Math With 10: Adding 10 to any single digit creates a teen number
Adding 10 to any single digit creates a teen number
10 + 7 = 17 (the 7 goes in the ones place)
10 + 7 = 17, which matches our mental calculation
10 + n = 1n (where n is the single digit)
10 + 7 = 17
• Ten Rule: Adding 10 increases the tens place by 1
• Pattern Recognition: 10 + n = teen number with n in ones place
• Mental Calculation: Solve quickly using known patterns
Place Value: The value of a digit based on its position in a number
Tens Place: The position that represents groups of ten
Ones Place: The position that represents individual units
Teen Numbers: Numbers from 11 to 19 that contain one ten and some ones
- Direct Addition: 10 + n = 1n (where n is the single digit)
- Place Value: Recognize 10 as 1 ten and n as n ones
- Make 10: Break numbers to form 10, then add remainder
- Mental Math: Use patterns and memorized facts
- Visual Representation: Use base-10 blocks or number lines
• 10 + 0 = 10: Identity property
• 10 + 1 = 11: First teen number
• 10 + 2 = 12: Second teen number
• 10 + 3 = 13: Third teen number
• 10 + 4 = 14: Fourth teen number
• 10 + 5 = 15: Fifth teen number
• 10 + 6 = 16: Sixth teen number
• 10 + 7 = 17: Seventh teen number
• 10 + 8 = 18: Eighth teen number
• 10 + 9 = 19: Ninth teen number
Use visual base-10 blocks
Base-10 Blocks: Visual representation using tens rods and ones cubes
One ten rod (█) represents 10
Six ones cubes (○○○○○○) represent 6
One ten rod + six ones cubes = 16
10 + 6 = 16
• Visual Representation: Helps understand place value
• Concrete Modeling: Physical objects aid comprehension
• Place Value: Tens and ones combined to form the total
Find the missing addend
Inverse Thinking: Using the inverse operation to find missing numbers
? + 10 = 18
To find the missing number, subtract 10 from 18
18 - 10 = 8
8 + 10 = 18 ✓
The missing number is 8
• Inverse Operations: Addition and subtraction are inverses
• Missing Addend: Subtract known addend from sum
• Verification: Check answer by substituting back
Place Value: The value of a digit based on its position in a number
Tens Place: The position that represents groups of ten
Ones Place: The position that represents individual units
Teen Numbers: Numbers from 11 to 19 that contain one ten and some ones
- Recognize the pattern: Adding 10 changes the tens place
- Understand place value: Tens and ones work together
- Apply mental strategies: Use known patterns and facts
- Verify the result: Check answers using different methods
• 10 + 0 = 10: Adding zero doesn't change the number
• 10 + 1 = 11: The first teen number
• 10 + 2 = 12: The second teen number
• 10 + 3 = 13: The third teen number
• 10 + 4 = 14: The fourth teen number
• 10 + 5 = 15: The fifth teen number
• 10 + 6 = 16: The sixth teen number
• 10 + 7 = 17: The seventh teen number
• 10 + 8 = 18: The eighth teen number
• 10 + 9 = 19: The ninth teen number