She gets $4 in allowance per week. Since we started giving the kids allowances, they've had piggy banks that are divided in three parts - the Church, the Bank, and the Store. They have to put 10% of their allowance in the Church, and this is put in the plate at Sunday School. The remainder goes half in the Bank (their long-term savings) and half in the Store (the amount they can s0pend). Any additional money they earn or get can be spent as they please.
They already know that 10% of a number is just throwing away the last digit. So, the other day, Unknown Daughter (7 years old and in first grade, BTW) asked how much $3.60 (the amount remaining after she takes 10% out of her $4.000) was when split in two. I asked her how much SHE thought it was. She went into the other room, and came out a few minutes later, saying $1.80. I asked her how she got this number, and this was her answer:
- I couldn't split $3 into two, but I can split $2 into 2 $1's . So this left me $1.60.
- I Don't know how to split $1.60, but that's just $1 and $0.60.
- So, I split the $1 into 2 $0.50's and the %0.60 into 2 $0.30's
- Then I added up the pieces - $1 + $0.50 + $0.30
She then noticed that the left hand column (the number of pieces) twice as big each time going down the column and the right hand side (the $$ value of each piece) got twice as big going UP the column. We did a few more examples at HER request (she thought the whole thing was a blast).
Finally, she went into her room and came out a few minutes later with a drawing of a girl with a crown on her head, titled "Unknown Daughter - The Math Princess".
Not bad for a first grader, eh? Of course, I'm totally unbiased.
Update (1/4/08): Unknown daughter came to me today and said "Daddy - I decided I don't want to be called the Math Princess. From now on, I want to be called the MATH RULER." That's my girl.