Which of the following represents (7 thousands +7 hundreds + 9 ones) ?
7790
779
7709
7009
7 thousands + 7 hundreds + 9 ones ⇒ 1000 × 7 + 100 × 7 + 10 × 0 + 1 × 9 = 7709
5 thousands + 3 hundreds + 1 tens + 5 ones + 7 tenths + 7 hundredths can be written as __________.
9 hundreds + 7 tens + 3 ones is 973.