Exchanging Money (Mental Math)
π§ The Bank Manager! There are no pictures of coins. You just have the math. Can you exchange the numbers flawlessly in your head?
Do this: Read the concept below, then try the quiz or activity.
Concept
You don't need pictures when you know the values of the coins. You just use Addition and Division!
π― The Manager's Test: "I have 3 Dimes and 5 Pennies. Give me the least amount of coins back!"
1. Calculate the total: 3 Dimes = 30c. 5 Pennies = 5c. Total = 35 cents. 2. Can I get a giant Quarter (25c)? Yes! * 35 - 25 = 10 cents left over. 3. Can I get a Dime (10c) for the rest? Yes! * 10 - 10 = 0! 4. Answer: Give them 1 Quarter and 1 Dime! (25 + 10 = 35c).
Instead of carrying 8 coins in their pocket, they now carry 2!
Try it
Manage the bank!
Instructions: Figure out the total value of the small coins. Then figure out what big coins you can trade it for!
Problem 1: Customer gives you: 4 Nickels (5, 10, 15, 20... 20 cents!) * What TWO coins can you give them back? * Answer: 2 ____________.
Problem 2: Customer gives you: 6 Nickels! (5x6 = 30 cents!). * What single Quarter can you use? (25c). How much is left over? (5c). * Which coin is worth 5 cents? * Answer: 1 _________ and 1 __________.
Problem 3: Customer gives you: 10 Pennies. * Give them back the single smallest silver coin! * Answer: 1 ________.
Problem 4: Customer gives you: 3 Quarters, 2 Dimes, 1 Nickel. * 3 Quarters = 75. 2 Dimes = 20. 1 Nickel = 5. (75 + 20 + 5 = 100!). * Answer: 1 ________ bill.