The big kids all played this at some stage too. Fiona wanted to give it a try today while she and I were taking an extra trip to Nelson. It goes like this:
"I'm thinking of a number that's bigger than 5 and smaller than 10."
"Is it 7?"
"Is it 8?"
"Yep! You got it!"
The variations are endless and when the parent is doing the "thinking of a number" the game can be used to stretch a child's understanding and interest into new areas. I've been known to try to "trick" my kids with fractions, negative numbers and irrational numbers. When played as a "multiple guess" game it's a great one for helping kids develop rational strategies based on probability. For instance, if the number is known to be between 50 and 100, 75 is a good guess, while 51 is not. It often takes kids practice to get the hang of that sort of problem-solving.
Today we played some "multiple guess" rounds, but I also tried pushing towards the limits of Fiona's conceptual understanding to see where those limits are. Among the questions she got:
"I'm thinking of a number that's how old Daddy will be in two years."
"I'm thinking of a number that's half Sophie's age."
"I'm thinking of a number that's two after 12 on a clock face."
"I'm thinking of a number that's one less than 0."
"I'm thinking of a number that's how many days there are in two weeks."
"I'm thinking of a number that's how many days there are in two weeks if you don't count the Saturdays."
"I'm thinking of a number that's double 8."
"I'm thinking of a number that's one less than two tens."
Among those she didn't get:
"I'm thinking of a two-digit number that's less than 11." (I don't think she really understands the difference between digits and numbers.)
"I'm thinking of a number that's halfway between 3 and 7."
Fiona is positively driven in the area of math lately. She's pouring just as much passion into this as she did into violin last spring and into painting through last winter. She's now almost three-quarters of the way through the Miquon Orange book, and this isn't half the math she does -- she's always peppering people with questions and announcing numerical relationships she's been working out. I thought Sophie was wild about math at this age, but she wasn't half as obsessed as Fiona.