how can the clerk make the change of the $1 bill using the fewest number of coins?

Two 50-cent pieces.

Is there more to this problem?

in book one side they say carlo had to buy on can of food because he ran out. he went to the store and bought a $0.79 can of food. he paid with a $ 1 bill. how much change did he get? ( this is different one in one question they put 5 parts in one question)

this answer is $0.21 left

no

What is the least number of coins that make up $0.21?

To make the change of a $1 bill using the fewest number of coins, the clerk can follow these steps:

1. Identify the available denominations of coins: In this case, common denominations could be pennies (1 cent), nickels (5 cents), dimes (10 cents), and quarters (25 cents).

2. Start with the largest denomination: To minimize the number of coins used, begin by using the largest denomination available. In this case, we would start with quarters.

3. Divide the total amount into quarters: Since each quarter is worth 25 cents, calculate how many quarters can be used to make up $1. Subtract the value of the quarters used from $1 to determine the remaining amount.

4. Move to the next largest denomination: If there is still a remaining amount, move on to the next largest denomination, which is dimes.

5. Divide the remaining amount into dimes: Determine how many dimes can be used to represent the remaining amount. Subtract the value of the dimes used from the remaining amount to determine any remaining change.

6. Continue with smaller denominations: If there is still remaining change, proceed with nickels and then pennies, following the same process as above.

By starting with the largest denominations first and working down to the smaller ones, the clerk can make the change using the fewest number of coins possible.