Common Mistakes
Everyone makes mistakes when learning! Let's look at common errors and learn how to avoid them.
Mistakes Help Us Learn!
Making mistakes is part of learning math. When we understand what can go wrong, we can be more careful and get the right answers!
Mistake #1: Counting One Number Twice
Sometimes when adding, kids count the first number again. This makes the answer too big!
The Wrong Way
Problem: 3 + 2 = ?
Counting: "1, 2, 3... 1, 2, 3, 4, 5" (starting over at 1 for the second group)
3 + 2 = 6 (Wrong!)
The Right Way
Keep counting from where you stopped!
Counting: "1, 2, 3... 4, 5" (keep going!)
3 + 2 = 5 (Correct!)
Mistake #2: Mixing Up + and -
The plus sign (+) and minus sign (-) look a little similar. It's easy to mix them up!
The Wrong Way
Problem: 5 - 2 = ?
Thinking it's addition: "5 plus 2 equals..."
5 - 2 = 7 (Wrong! That's 5 + 2)
The Right Way
Look carefully at the sign!
+ means ADD (put together, get MORE)
- means SUBTRACT (take away, get LESS)
5 - 2 = 3 (Correct! We took away.)
Mistake #3: Skipping Numbers When Counting
When we count too fast, we might skip a number and get the wrong answer!
The Wrong Way
Problem: 4 + 3 = ?
Counting too fast: "1, 2, 3, 4, 5, 7" (skipped 6!)
4 + 3 = 6 (Wrong!)
The Right Way
Count slowly and touch each object!
Counting carefully: "1, 2, 3, 4, 5, 6, 7"
4 + 3 = 7 (Correct!)
Mistake #4: Counting the Same Object Twice
Sometimes we count an object more than once, which makes our answer too big!
The Wrong Way
Problem: How many cookies?
Counting: "1, 2, 3, 3, 4, 5, 6" (counted one cookie twice!)
Answer: 6 (Wrong!)
The Right Way
Move objects as you count, or cross them off!
Counting: "1, 2, 3, 4, 5" (point and move to one side as you count)
Answer: 5 (Correct!)
Mistake #5: Subtracting in the Wrong Direction
In subtraction, we always start with the BIGGER number first!
The Wrong Way
Problem: 6 - 4 = ?
Starting with 4 and taking away 6: "I can't take 6 from 4..."
This causes confusion!
The Right Way
Start with the first number (the bigger one) and take away!
Start with 6 balloons. Take away 4. Count what's left: 1, 2.
6 - 4 = 2 (Correct!)
Practice: Avoid the Mistakes!
Now that you know what to watch out for, try these problems carefully!
Be Careful and Solve These!
Problem 1: Look at the sign carefully!
3 + 2 = ?
Problem 2: This is SUBTRACTION!
5 - 2 = ?
Problem 3: Count carefully - don't skip!
4 + 4 = ?
Problem 4: Start with 7, take away 3!
7 - 3 = ?
Problem 5: Keep counting - don't start over!
5 + 3 = ?
Checklist: Before You Answer
Ask yourself these questions:
- Did I look at the sign? Is it + (add) or - (subtract)?
- Did I count slowly and carefully?
- Did I touch each object only once?
- Did I keep counting (not start over)?
- Does my answer make sense?
Remember These Tips!
Look at the Sign
+ means add
- means subtract
Touch and Count
Point to each object as you count
Go Slowly
Take your time to count carefully
Keep Going
Don't start counting at 1 again when adding
What's Next?
- Practice counting slowly with objects at home
- Always check the sign before solving
- Take the Unit Quiz to show what you've learned!