Use the associative property.

In which property, do we partition numbers?

Think of distributive property of whole numbers.

Think any number, when we multiply it by any number gives the same answer.

First find, the total money he would earned in one day and then find the total money he would earned in 30 days.

In which two operations, there will be no affect on answers even by changing the order of numbers.

Think about how the digits are being added in the next row each time.

Think about multiplying a whole number by zero.

Think any number, which gave you the same number as an answer after addition.

Use distributive property