Question

coins
welcome to math challenge #8! this challenge is all about coins and money! coins are part of everyday life — you might have used them to buy a snack, saved them in a piggy bank, or even earned them from a lemonade stand. if you havent learned about coins yet, this is a great time to get familiar with coins and their values.
in the u.s., we have coins worth 1¢ (penny), 5¢ (nickel), 10¢ (dime), 25¢ (quarter), 50¢ (half dollar), and $1.00 (dollar coin).
dollar coins have been minted in the united states in gold, silver, and base metal versions. however, since 2012, the u.s. mint makes most dollars for collecting.
but its still possible youll see one in your change.

you will use your logical thinking and problem - solving skills to figure out how coins can be combined to make different amounts of money. get ready to think carefully, be creative, and have fun exploring how math shows up in the real world!
kinder & first grade: solve at least 3 problems.
second & third grade: solve at least 7 problems.
fourth grade and above: solve at least 12 problems.

1. laura knows that each nickel is worth 5 cents and each penny is worth 1 cent. if laura has 2 nickels and 2 pennies, how much money (in cents) does she have?

1. donna has two different coins, and they add up to 15 cents. what are the coins?

$\bigcirc + \bigcirc = 15\text{¢}$

1. mia has 3 dimes and 4 nickels. how much money does she have?

1. liam wants to buy a toy that costs 85¢. he has three quarters and two dimes. does he have enough money?

Explanation:

Problem 1

Step1: Calculate value of nickels

Each nickel is 5 cents, 2 nickels: \(2\times5 = 10\) cents.

Step2: Calculate value of pennies

Each penny is 1 cent, 2 pennies: \(2\times1 = 2\) cents.

Step3: Sum the values

Total: \(10 + 2 = 12\) cents.

We know coin values: penny (1¢), nickel (5¢), dime (10¢), quarter (25¢), half - dollar (50¢). We need two different coins that sum to 15¢.
Check combinations:

• Dime (10¢) and nickel (5¢): \(10 + 5=15\)¢. Other combinations (like quarter and others) won't work as quarter is 25¢ which is more than 15¢, and penny and nickel/dime combinations: 1 + 5 = 6, 1+10 = 11, etc. don't sum to 15.

Step1: Calculate value of dimes

Each dime is 10 cents, 3 dimes: \(3\times10 = 30\) cents.

Step2: Calculate value of nickels

Each nickel is 5 cents, 4 nickels: \(4\times5 = 20\) cents.

Step3: Sum the values

Total: \(30+20 = 50\) cents.

Answer:

12 cents

Problem 2