Well, I wrote you a few words myself. I don't know if it's enough Ask me for it again.

Do an arithmetic problem orally.

8+8÷8+8

5+7×9

77+33-55+ 1 1

3+3+3+3+3+3+3+3+3+3+3

Vertical (to be inspected)

888888+333333

37848×6

77×77

5 14÷ 13

103÷7

Recursive equation (skilled calculation means skilled calculation)

1+3+6+5+7+8+ 10+9+2+4

77×99÷99×77

99×99+99× 1+(98+ 1)× 1

As time is tight, you can solve the problem yourself by searching online.