Write a program name dollars that calculates and displays the conversion of an entered number of dollars into currency , 10s, 5s, and 1s.

I will code in Javascript.

Preconditions:

function Dollars(dollar) {

//declare and initialize the variables.

 var twenties = 0;

 var tens = 0;

 var fives = 0;

 var ones = 0;

//If dollar is greater or equals 20, divide dollar by 20 and save it into the variable twenties. Then, save the remainder into the variable dollar.  

 if(dollar >= 20){

   twenties = Math.floor(dollar/20);

   dollar = dollar % 20;

 }

//If dollar is greater or equal 10, divide dollar by 10 and save it into the variable twenties. Then, save the remainder into the variable dollar.  

 if(dollar>=10){

   tens = Math.floor(dollar/10);

   dollar = dollar % 10;

 }

//If dollar is greater or equal 5, divide dollar by 5 and save it into the variable twenties. Then, save the remainder into the variable dollar.  

 if(dollar>=5){

   fives = Math.floor(dollar/5);

   dollar = dollar % 5;

 }

//If dollar is greater or equal 1, divide dollar by 1 and save it into the variable twenties. Then, save the remainder into the variable dollar.  

 if(dollar>=1){

   ones = Math.floor(dollar/1);

   dollar = dollar % 1;

 }

//At this point, dollar is equal 0.It's time to display the conversion.

Console.log('20s :' + twenties);

Console.log('10s :' + tens);

Console.log('5s :' + fives);

Console.log('1s :' + ones);

}

Explanation:

The variable Math.floor(num) is used to round a number downward to its nearest integer.

For example, if dollar=57:

twenties = dollar/20 will be 57/20 = 2

dollar = dollar % 20 will be 57 % 20 = 17

tens = dollar/10 will be 17/10 = 1

dollar = dollar % 10 will be 17 % 10 = 7

fives = dollar/5 will be 7/5 = 1

dollar = dollar % 5 will be 7 % 5 = 2

ones = dollar/1 will be 2/1 = 2

dollar = dollar % 1 will be 0 % 5 = 0