Addition: Combining two or more numbers to find a total
- Start with the first number (3)
- Count up 4 more: 4, 5, 6, 7
- The answer is 7
We need to add 3 and 4
Start at 3 and count 4 more: 4, 5, 6, 7
The last number counted is the answer
3 + 4 = 7
3 + 4 = 7
• Counting on: Start with the larger number
• Sequential counting: Count each number in sequence
• One-to-one correspondence: Each count represents one added
Number 5: A benchmark number that helps with addition
We need to add 5 and 2
Start at 5 and count 2 more: 6, 7
The last number counted is the answer
5 + 2 = 7
5 + 2 = 7
• Counting on: Start with the larger number
• Number 5: Helps build number sense
• Sequential counting: Count each number in sequence
Addition with zero: Adding zero doesn't change the number
We need to add 6 and 0
Adding zero means nothing is added
The first number doesn't change
6 + 0 = 6
6 + 0 = 6
• Zero property: Any number + 0 = the same number
• Identity element: Zero doesn't change the value
• Conceptual understanding: Nothing added means no change
Subtraction: Taking away one number from another to find the difference
We start with 7 and take away 3
Start at 7 and count 3 back: 6, 5, 4
The last number counted is the answer
7 - 3 = 4
7 - 3 = 4
• Counting back: Move backwards on the number line
• Sequential counting: Count each number in sequence
• Subtraction: Taking away reduces the total
Subtraction with 5: Using 5 as a benchmark for subtraction
We start with 8 and take away 5
Start at 8 and count 5 back: 7, 6, 5, 4, 3
The last number counted is the answer
8 - 5 = 3
8 - 5 = 3
• Counting back: Move backwards on the number line
• Number 5: Helps build number sense
• Subtraction: Taking away reduces the total
Subtraction of same numbers: Taking away the same number results in zero
We start with 4 and take away 4
When you take away all of something, you have nothing left
4 - 4 = 0
4 - 4 = 0
4 - 4 = 0
• Subtraction property: Any number - itself = 0
• Zero result: Taking away all leaves nothing
• Conceptual understanding: Nothing remains after complete removal
Within 10 Practice
Addition & Subtraction
Addition: Combine groups
Subtraction: Take away
Practice Makes Perfect!
This section provides a comprehensive overview of addition and subtraction within 10, including definitions, methods, strategies, and key concepts for 1st grade students.
Addition: Combining numbers to find a total or sum.
Subtraction: Taking away one number from another to find the difference.
Within 10: Problems where the answer is 10 or less.
Counting On: Starting with the larger number and counting up.
• Addition increases the total
• Subtraction decreases the total
• The sum of two numbers within 10 will never exceed 10
• Order doesn't matter in addition (commutative property)
Counting On: Start with the larger number and count up
Using 5 as a Benchmark: Helps with number sense
Adding Zero: Adding zero doesn't change the number
Number Bonds: Understanding parts that make a whole
Counting Back: Start with the larger number and count down
Using 5 as a Benchmark: Helps with number sense
Subtracting Zero: Subtracting zero doesn't change the number
Subtracting Same Numbers: Results in zero
Addition: 3 + 4 = 7 (start at 3, count 4: 4, 5, 6, 7)
Subtraction: 7 - 3 = 4 (start at 7, count back 3: 6, 5, 4)
With Zero: 6 + 0 = 6, 5 - 0 = 5
Same Numbers: 4 - 4 = 0
• Start with the larger number when counting on
• Practice doubles facts regularly (they help with near doubles)
• Use fingers or drawings if needed initially
• Always check your answer by counting again
Questions & Answers
Question: Why do we practice addition and subtraction within 10? Is it important?
Answer: Yes, it's very important! Practicing within 10 helps you:
- Build number sense: Understanding how numbers work together
- Create a foundation: These skills help with bigger numbers later
- Develop fluency: Quick recall of basic facts
- Improve mental math: Calculating in your head
- Prepare for word problems: Real-world applications
Think of it like learning the alphabet before reading books - mastering small numbers makes bigger math easier!
These basic facts become automatic, freeing up your brain for more complex problems.
Question: My child is still counting on their fingers for addition and subtraction. Should I be concerned, and how can I help them move beyond finger counting?
Answer: Finger counting is completely normal and appropriate for 1st graders! Don't worry - it shows your child is developing number sense.
Here are strategies to help transition from finger counting:
- Use visual aids: Number lines, ten frames, or dot cards
- Practice mental math: Start with very easy problems and gradually increase
- Teach efficient strategies: Counting on from the larger number
- Build fluency: Regular practice with doubles and near doubles
- Gradual reduction: Encourage "just trying it in your head" for easier problems
Focus on building number relationships and strategies rather than rushing to eliminate finger counting. The mental strategies will develop naturally with practice and exposure to different approaches.
It typically takes several months of consistent practice to reduce reliance on finger counting.
Question: How do I know when to add and when to subtract? Sometimes I mix them up!
Answer: Great question! Here's how to tell:
Addition words: "more," "added," "total," "altogether," "in all," "combined"
Subtraction words: "left," "remaining," "takes away," "eats," "loses," "gives"
Think about what's happening:
- Addition: Something is being added or joined together
- Subtraction: Something is being taken away or separated
For example:
- "Sarah has 3 apples and gets 2 more" → ADDITION (she has MORE)
- "Tom had 5 cookies and ate 2" → SUBTRACTION (he has FEWER)
When in doubt, draw a picture to help visualize what's happening!