There are 400 quarters in 400. If you would like to convert quarters to some other unit of measure you need to say what you want to convert into, like dollars or dimes or pounds.
400 quarters
400
400
400 quarters = $100
You can cut the 100 dollar bill into 4 quarters. (Whether this is legal or not is a different matter.) a quarter = $0.25 → $1 = 4 quarters → $100 = 100 × 4 quarters = 400 quarters → there are 400 quarters in $100.
400 quarters
1600 quarters
400
400
400
400
400
400
400 quarters = $100
100 4 400
You can cut the 100 dollar bill into 4 quarters. (Whether this is legal or not is a different matter.) a quarter = $0.25 → $1 = 4 quarters → $100 = 100 × 4 quarters = 400 quarters → there are 400 quarters in $100.
400 dollars