Answer:
524 - (10) 520, (100) 500, (1,000) 1000
2,679 - (10) 2,680, (100) 2,700, (1,000) 3,000
12,405 - (10) 12,400, (100) 12,400, (1,000) 12,000

Answer:
50      1,222      15,000.25
To halve a number, divide it by two.

Answer:
99      201.6      329.97

The grand total is: 630.57