Sally decided to decorate her bedroom. She wasn’t sure how many rolls of wallpaper she would need but she knew that her friend, Meghan next door had recently done the same job and the two rooms were identical in size.
“Meghan,” she said, “How many rolls of wallpaper did you buy for your bedroom?”
“Ten,” said Meghan.
So Sally bought ten rolls of paper and did the job, but had 2 rolls left over.
“Meghan,” she said. “I bought ten rolls of wallpaper for the bedroom, but I’ve got 2 left over!”
“Yes,” said Meghan.
“So did I.“