300 + 300 + 300 + 100
= 300 x 3 + 100
= 900 + 100
= 1000
90 + 10 + 900
= 100 + 900
= 1000
300 + 300 + 300 + 100
= 300 . 3 + 100
= 900 + 100
= 1 000
90 + 10 + 900
= 100 + 900
= 1 000
300 + 300 + 300 + 100 = 1000
90 + 10 + 900 = 1000
300 + 300 + 300 + 100 = 1000
90 + 10 + 900 = 1000