(Answers)
Standard form: 15,409
Expanded form: 10000 + 5000 + 400 + 9
Word form: Fifteen thousand four hundred and nine.
Step-by-step explanation:
In standard form, we start from the right side of the number and after every third digit from the right side, the comma should be place. Hence it would be 15,409.
In expanded form, we write in simple addition form like 10000 + 5000 + 400 + 9 = 15409.
In word form, we usually read in plain English like: Fifteen thousand four hundred and nine.