Found Their Marbles
(page 65)

Here we have a solution to Found Their marbles (page 65) from some sixth-graders in New England. Look at what they've done. What do you like about their presentation? What else could they have done? (hint: what was the original question in the problem??)

This solution is from Allison Fox, Sam McGrath, Reagan Teed and Kimmy Schmidt from Mr. Welch's sixth grade math class at Williams Middle School in Longmeadow Massachusetts.
We think we have the solution to the problem, Found Their Marbles.
Calvin has 16,384 marbles. Xavier has 3,000 marbles. Alice has 4,650 marbles.
We got Calvin's by using a chart: 

 Days      Marbles
 
 
 2            1
 4            2
 6            4
 8            8
10           16
12           32
14           64
16          128
18          256
20          512
22        1,024
24        2,048
26        4,096
28        8,192
30       16,384
 
 
We got Alice's by also using a chart:

Days        Marbles
1             10
2             20
3             30
4             40
5             50
6             60
7             70
8             80
9             90
10           100
11           110
12           120
13           130
14           140
15           150
16           160
17           170
18           180
19           190
20           200
21           210
22           220
23           230
24           240
25           250
26           260
27           270
28           280
29           290
30           300

Then, we added all of the totals up and got 4,650.
We got Xavier's total by multiplying 30 times 10 and got 3,000. So Xavier had 3,000 marbles.

What do you think about this solution? Want to put in one of your own? Just write to

back to the Answer Book page