Regrouping Multiple Place Values

Subtract: 500 - 258
Exact difference:

I can't borrow from the tens place, because there are 0 tens.
I will borrow from the hundreds place to make _ tens.
I'm giving one of those tens to the ones place.

500
-258
------
____

Estimated difference:
500
-250
-------
____

Therefore, our answer is reasonable.

1 answer

Let's work through the problem step-by-step:

Exact Difference: 500 - 258

  1. Set up the problem:

      500
    - 258
    
  2. Subtract from the ones place:

    • Since we have 0 in the ones place of 500, we cannot subtract 8 from 0. So, we need to borrow from the tens place.
  3. Borrowing from the tens place:

    • We can't borrow directly from the tens place (0 tens) but can borrow from the hundreds. We take 1 hundred (making 400) and convert it into 10 tens. Now, we have 10 tens in the tens place and 0 in the ones place.
    • This means we now have 10 ones (from the tens we just made).
  4. Now, we perform the subtraction:

    • From the ones place: \(10 - 8 = 2\)
    • We have borrowed 1 ten, so we have 9 tens left in the tens place. Now subtract the tens: \(9 - 5 = 4\)
    • Finally, in the hundreds place: \(4 - 2 = 2\)
  5. Putting it all together:

      500
    - 258
    ------
      242
    

Estimated Difference: 500 - 250

  1. Set up the estimation:

      500
    - 250
    
  2. Perform the subtraction directly:

    • In the ones place: \(0 - 0 = 0\)
    • In the tens place: \(0 - 5\) (can’t do this, so we also need to borrow):
      • Borrowing from the hundreds makes the first digit 4 and gives us 10 in the tens place.
    • Now we have \(10 - 5 = 5\)
    • In the hundreds place after borrowing: \(4 - 2 = 2\)
  3. Putting it all together:

      500
    - 250
    ------
      250
    

Conclusion

The estimated difference was found to be 250. The exact difference is 242.

Both calculations yield reasonably close results, indicating that our subtraction is correct.

Final Answer:

  • Exact difference: 242
  • Estimated difference: 250
  • Therefore, the answer is reasonable.