Stealing Eggs

Date: 04/17/97 at 22:07:29
From: Brian Gage
Subject: Stealing eggs

There are 10 children going on an Easter egg hunt. Every child finds 
10 eggs.  Suddenly a mean child steals one egg from each child. How 
many eggs are left?

Alessandra (age 8)

Date: 04/18/97 at 19:13:22
From: Doctor Jodi
Subject: Re: Stealing eggs

Dear Alessandra,

Thanks for your word problem. First of all, if you can, you might want 
to find some pennies or bingo counters or something like that to help 
you count all these things.

First we have 10 children, with 10 eggs each.  How many eggs is that?
Let's make a list of the children and how many eggs each has:

 Child 1: 10
 Child 2: 10
 Child 3: 10
 Child 4: 10
 Child 5: 10
 Child 6: 10
 Child 7: 10
 Child 8: 10
 Child 9: 10 
Child 10: 10

Can you add those all up?  (If you do this with piles of pennies or 
bingo chips, you can make 10 piles of 10 and count them up.)

We have a shorthand for adding something to itself a certain number of
times. It's called multiplication. Here's 2 X 3, for example:

  **
  **
  **

How would you write your addition problem as multiplication?

Now that you have the total, we have to see what happens next. Next 
someone comes along and steals 1 egg from each child. How many eggs is 
that?

Here's another list of the number of eggs stolen from each child:

 Child 1: 1
 Child 2: 1
 Child 3: 1
 Child 4: 1
 Child 5: 1
 Child 6: 1
 Child 7: 1
 Child 8: 1
 Child 9: 1 
Child 10: 1

We can also write that as 10 x 1.

Next we take the first number of eggs (100) and subtract the number of
eggs stolen (10). Can you figure out what we get using pennies or 
counters?

There's another way to answer this problem: you can subtract the egg 
stolen from each child first and then multiply ten times the number of 
eggs left. What do you think would happen then?

Write back if you have more questions or need more help.

-Doctor Jodi,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/