Estimate the sum of `5390 and 715` by rounding off the numbers to their nearest hundreds and tens respectively.

Answer

To estimate the sum of 5390 and 715 by rounding off the numbers to their nearest hundreds and tens respectively, follow these steps:

### Step 1: Round 5390 to the nearest hundred
- Look at the last two digits of 5390, which are 90.
- The digit in the tens place is 9, which is greater than 5.
- Therefore, we round up the hundreds place (3) by 1, making it 4.
- Thus, 5390 rounded to the nearest hundred is **5400**.

### Step 2: Round 715 to the nearest ten
- Look at the last digit of 715, which is 5.
- Since the digit in the units place is 5, we round up the tens place (1) by 1.
- Thus, 715 rounded to the nearest ten is **720**.

### Step 3: Add the rounded numbers
- Now, add the rounded numbers: 5400 and 720.
- Calculation:
\[ 5400 + 720 = 6120 \]

### Final Answer
The estimated sum of 5390 and 715, after rounding, is **6120**.

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