Let’s learn how to add and subtract two-digit numbers! It’s like a fun puzzle where we line up numbers and solve them step by step. Ready? Let’s go!
When we add two-digit numbers, we need to line them up nicely. We write one number on top of the other, making sure the ones and tens columns match up.
Sometimes, when we add the ones column, the sum is ten or more. This is when we need to regroup.
Subtracting is like taking away. We also line up the numbers vertically, making sure the ones and tens columns match.
Sometimes, the top number in the ones column is smaller than the bottom number. This is when we need to regroup.
Great job! Now you know how to add and subtract two-digit numbers. Keep practicing, and you’ll get even better!
Here’s a sanitized version of the provided transcript:
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**Adding and Subtracting Two-Digit Numbers**
When adding two-digit numbers, it is important to line them up correctly. We write them vertically, one number below the other, ensuring that the ones column of the top number aligns with the ones column of the bottom number. The tens column must also be aligned.
There are two steps when adding two-digit numbers:
1. **Add the Ones Column**: For example, with 57 and 12, the 7 and the 2 are in the ones column. We add them first: 7 plus 2 equals 9.
2. **Add the Tens Column**: The 5 and the 1 are in the tens column. We add them next: 5 tens plus 1 ten equals 6 tens.
**Adding with Regrouping**
When adding two-digit numbers, you may need to regroup after adding the ones column if the sum is ten or more. Ten ones are regrouped into one ten.
1. **Add the Ones Column and Regroup if Necessary**: For example, with 26 plus 17, the 6 and the 7 are in the ones column. Adding them gives us 6 plus 7, which equals 13. Since 13 is greater than 10, we need to regroup. Thirteen equals one ten plus three ones, so we place the 3 in the ones column and regroup the 1 to the tens column.
2. **Add the Tens Column**: Now we add the tens column. We have 1, 2, and 1 in the tens column. One ten plus two tens plus one ten equals four tens. Therefore, the answer is 43.
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**Subtracting Two-Digit Numbers**
When subtracting two-digit numbers, we must also line them up correctly, writing them vertically. The ones column of the top number should align with the ones column of the bottom number, and the tens column must be aligned as well.
There are two steps when subtracting two-digit numbers:
1. **Subtract the Ones Column**: For example, with 37 minus 14, the 7 and the 4 are in the ones column. We subtract them first: 7 minus 4 equals 3.
2. **Subtract the Tens Column**: The 3 and the 1 are in the tens column. We subtract them next: 3 tens minus 1 ten equals 2 tens. Therefore, 37 minus 14 equals 23.
**Subtracting with Regrouping**
When subtracting two-digit numbers, we need to regroup if the top number in the ones column is smaller than the bottom number.
1. **Regroup if Necessary and Subtract the Ones Column**: For example, with 41 minus 15, the 1 and the 5 are in the ones column. We cannot subtract 5 from 1 because 1 is less than 5, so we need to regroup. We take 1 ten away from 4, turning it into 3 tens, and regroup it into 10 ones. Now, the 1 becomes 11 ones. We can now subtract: 11 minus 5 equals 6.
2. **Subtract the Tens Column**: Since we took one ten away, we have 3 tens remaining. So, 3 tens minus 1 ten equals 2 tens. Therefore, 41 minus 15 equals 26.
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