It was a bright and cheerful morning in Numberland. The sun shone on tents and stalls lined up for Market Day. The air buzzed with excitement, animals chattered, coins jingled. Everyone was ready to buy and sell their favorite things.

At the first stall stood Tim the Tortoise, who sold antique trinkets. He was kind and patient, but there was one small problem: Tim was very forgetful. Sometimes he forgot prices, and sometimes he gave the wrong change!

Next to Tim was Sam the Squirrel, bouncing from place to place with a pouch full of coins. But Sam was very messy. His pennies, nickels, dimes, and quarters were all mixed together. 

At the end of the row was Ruby the Rabbit. She was quick, clever, and loved numbers. Ruby was selling her famous carrot muffins for five dollars each and she always gave the exact change.

The morning started well, until Sam ran to Tim’s stall to buy a shiny old ring.

“How much for this one?” Sam asked, pointing at a ring with a sparkly big blue gem.

“That’ll be fifteen dollars and forty-five cents,” said Tim proudly.

Sam dug through his pouch. “Let’s see... one, two, three... oh no! My coins are all mixed up again!” He dropped a handful of change on the table. Nickels rolled, pennies spun, and quarters bounced away.

Ruby hopped over. “Don’t worry, Sam,” she said kindly. “Let’s count together by skip-counting.”

She lined up the nickels: “Five, ten, fifteen, twenty-five, thirty, thirty-five. There’s thirty-five cents on the table. Sam, how much more money do you need to be able to buy the ring?” 

$15.45

  $0.35

-______

= ?

$15.45

  $0.35

-______

$15.10

“I have it! I need fifteen dollars and forty-five cents. If I already have thirty-five cents that means I need fifteen dollars and ten cents!” Sam proudly squeaked.

With Ruby’s help, Sam used one ten dollar bill and six one-dollar bills and smiled. “Got it! Sixteen dollars and thirty-five cents! Tim, may I have change?”

Tim nodded and handed him his ring, but instead of giving Sam the correct change, Tim accidentally gave him ten dollars!

Sam’s eyes widened. “Wow! Thanks, Tim!”

If Sam paid Tim $16.10, Tim must pay Sam back because that's more than what the ring cost. 

$16.10

$15.35

-______

= ?          

Ruby gasped. “Wait, Tim! No, that’s not right. Sam paid Sixteen dollars and ten cents for your ring!”

Tim blinked. “Oh dear... I can never remember how to properly give change!”

Ruby thought for a moment. “Let’s figure it out together. If Sam gives you sixteen dollars and ten cents, and the ring costs fifteen dollars and forty-five cents, how much change should he get?”