how we write 666

(a)  

how we write 1,000

(a)  

how we write 8,000

(a)  

how we write 123

(a)  

how we write 900

(a)  

how we write 120

(a)  

how we write 111

(a)  

how we write 1000

(a)  

how we write 2021

(a)