As a number it is: 21,000
14*10000+12000 = 152000
To write 400 thousand in numbers, you would write 400,000. This is a standard way to represent large numbers using commas to separate the thousands, millions, billions, etc. In this case, 400 is followed by three zeros to indicate the thousands place.
.0613
4,490
68,754
4589
To write 21 thousands, you express it as 21,000. This is achieved by multiplying 21 by 1,000, which represents one thousand. In numerical form, 21,000 indicates that there are 21 groups of one thousand.
7.0015
It is 410,000
90.16
129,000
915,000
14*10000+12000 = 152000
21,000 (grand in this sense means 'thousands')
279,800
13,270
640 thousands = 640,000