2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

= 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 - 1

\(=\dfrac{9.10}{2}-1=45-1=44\)

3000 + 4000 + 2000 = 9000

2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 44

3000 + 4000 + 2000 = 9000

Goku,you copied my answer and told other members to give you some points.