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Let's break down 4 into a smaller addition problem:
Now we'll get the exercise:
Since the exercise only involves addition, we'll use the commutative property and start with the exercise:
Now we'll get the exercise:
Let's solve the exercise from right to left:
21
\( 100-(30-21)= \)
Breaking down numbers can make addition easier by creating groups of 10! When you have 1+9=10, it's much simpler to work with than other combinations.
No! The commutative property means . You can rearrange numbers to make calculation easier, like grouping numbers that make 10.
If your check gives a different result, slow down and redo each step. Common errors happen when adding quickly - take your time with each addition!
Yes! Look for number pairs that make 10 or other easy sums. In this problem, you could also do (4+8)=12, then 12+9=21.
You can add from either direction! The explanation showed 10+8=18, then 18+3=21. This is just another valid way to reach the same correct answer.
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