Sheila wants to test the reasonableness of her answer to the expression below by using compatible numbers.

Question

Negative 8 + 19 + 8

Which equation would help Sheila do this?
10 + 20 + 10
–10 – 20 + 8
–10 + 20 + 10
10 + 20 – 8

Answer 1

To test the reasonableness of the expression \(-8 + 19 + 8\) using compatible numbers, Sheila should aim to use numbers that are easy to work with but close to the original numbers.

Looking at the given options, we want to find a set of numbers that is close to \(-8\), \(19\), and \(8\).

The expression can be simplified as follows:

1. \(-8\) can be rounded to \(-10\).
2. \(19\) can be rounded to \(20\).
3. \(8\) can be rounded to \(10\).

So a compatible number equation would be: \(-10 + 20 + 10\)

This helps Sheila estimate the result.

Therefore, the correct choice is: –10 + 20 + 10