Question

Number 2.3.4 is correct ? what else i should add?

Answer 1

In question 1)

The doubles fact is 2+2, and notice that

`2+3=2+2+1=(2+2)+1`

Thus, you need to circle the plus sign below 2+3.

On the other hand,

`2+1=2+2-1=(2+2)-1`

Therefore, you need to circle the minus sign below 2+1

Similarly, circle the plus sign below 2+4 and 4+5, and circle the minus sign below 3+2 and 4+3