Question

Isabel tried to evaluate an expression step by step.

\quad\begin{aligned} &(2+8)+8\\\\ \\ =&2+(8+8)&\green{\text{Step } 1} \\\\ \\ \\ =&2+0&\blue{\text{Step } 2}\\\\ \\ \\ =&2&\purple{\text{Step } 3} \\\\ \\ \\ \end{aligned}
=
=
=
​

(2+8)+8
2+(8+8)
2+0
2
​

Step 1
Step 2
Step 3
​

Find Isabel's mistake.

Answer 1

Step three

Explanation:

(2+8)+8

2+(8+8)

2+0

2

In the third step Isabel subtracted 8 into 8 not added, in order to evaluate the expression correctly she needed to add 8 into 8 and then add the two.

`(2+8)+8`

`2+(8+8)`

`8+8=16`

`2+16=18`

`=18`

Hope this helps.

Answer 2

• Step 3

Explanation:

1. (2+8)+8
2. 2+(8+8)
3. 2+0 mistake, 8 + 8 ≠ 0, should be 16 instead of zero
4. 2