Question

Add: 57 + 86
Estimate: 57 + 86
_ + 90 = 150
We can expect the estimate to be _ than the actual sum.
Set the problem up vertically. Line up the numbers by place value: ones over ones and tens over tens.
Add:
7 + 6 = _
10 + 50 + 80 = _
The total in the tool is _.
This is close to our estimate of 150.

Answer 1

Let's break this down step by step:

1. **Add:**
\( 57 + 86 \)

Line up the numbers by place value:

57
+ 86
-----

Now, adding the ones column:
- \( 7 + 6 = 13 \) (write down 3 and carry over 1)

Add the tens column:
- \( 5 + 8 + 1 = 14 \)

So, the total is:
\( 143 \)

2. **Estimate:**
For estimating \( 57 + 86 \), we can round:
- \( 57 \) rounds to \( 60 \)
- \( 86 \) rounds to \( 90 \)

So, \( 60 + 90 = 150 \).

3. **Find the missing number (_):**
To fill in the blank \( _ + 90 = 150 \):
\( 150 - 90 = 60 \)
So, the missing number is \( 60 \).

4. **Expectations about the estimate vs. actual sum:**
We can expect the estimate to be ***greater*** than the actual sum. (Since \( 150 \) is greater than \( 143 \)).

5. **Setting the problem up vertically again for clarity:**

57
+ 86
-----

- Adding again:
\( 7 + 6 = 13 \) (write down 3 and carry over 1)
\( 5 + 8 + 1 = 14 \)

Thus, the total is still \( 143 \).

6. **Summarizing:**
- The total in the tool is ***143***.
- This is close to our estimate of ***150***.

Final answers:
- Estimated sum: \( 150 \)
- Actual sum: \( 143 \)
- Difference between estimate and actual: Estimate is ***greater***.