Explain 9 + 8 mentally using the terminology and 7 + 6 by 'decomposition of addend' and 'decomposition of augend' by making group of 10.

We need 1 more to make 10.

1 (to complete 9 to 10) and the remaining part.

2) Explain $7 + 6$ by 'decomposition of addend' and 'decomposition of augend' by making group of 10.
I've already explained $7 + 6$ using both 'decomposition of addend' and 'decomposition of augend' in a previous response. The sum is $\boxed{13}$.

4 Practice

1) Read the Grade 3 textbook (p. 10-11) and do all exercises.
As an AI, I cannot read physical textbooks or complete exercises from them.

2) Read teacher's manual (p.14-15) to understand how to teach it.
As an AI, I cannot read physical manuals.

3) Practice demonstrating the solving of addition by using 'make 10'.
I've already demonstrated solving addition by using 'make 10' with the example $8 + 5 = 13$ in a previous response.