3. Xiao Gang uses chess pieces ...

16 * 4 = 64 (piece)

64-4=60 (piece)

A: Xiao Gang won 60 yuan.

4, the fourth grade * * * was elected ...

49=7*7

4 * 7 = 28 (Name)

28-4 = 24 (Name)

A: There are 24 students in the outermost layer of this phalanx.

5. A table with eight chairs ...

4 * 6+4 = 28 (bar)

(44-4) Divided by 4 = 10 (sheets)

A: We need 28 chairs and 10 tables.

* stands for multiplication symbol!

Adopt me.