Mystery Op 2
(page 37)

Here we have a number of solutions from a school in Michigan. Later in this file, there's one from Los Angeles.

Dear Solution Page,

The following solutions to Mystery Op 2 are from some Fifth Graders at Sylvester Elementary School, Berrien Springs, MI. We really hope that you will use our solutions on your solution page.


The students in Mrs. Lippi's Fifth Grade class

For Mystery Op # 2 , we first multiplied the numbers in the parentheses. Then we took away one from that answer. Then we multiplied the first number by the answer we got from solving the parentheses first , and took away one from that. With that we did the same for the rest. That's how we got the answer. If there are no parentheses then we just multiply it and subtracted it.

By Gabby Saitz and Amber Fryman

The answer we got was to multiply the numbers in the parentheses, then minus 1, and multiply the other numbers. You will have to minus 1 again. Minus 1 for each block. You will get the answer that way.

By: Senaida Alejandro

Okay. The way we got the answer was...

First, we multiply. Then you take away one from the product. If there is parentheses, we do that first, and then take away one. You would only multiply the first two numbers, then from the product, you would take away one. If you do this, I'm sure you'll get the right answer.

By: Kristin Lee

Answer to Mystery Op 2 Our answer was multiply the first two numbers and then subtract one. We got our answer by trying out different numbers until we found the answer. We used this operation in the parentheses first.

By Tony Beall, Ruben Tenorio, Ryan Little, and Joey Furner


We found two math signs that would work for all six problems

Example: 5#5=24 1#1=0

ANSWER: 5X5 -1=24 1X1 -1=O



And from Los Angeles...

We are two fifth grade students from Los Angeles, California. We were trying to find the answer to the problem called Mystery Op 2 and we noticed a pattern. We saw that in each equation if you just put a multiplication sign in between the numbers it equals one more than the right side of the equation. We think that the answer has to be multiply by the second number then subtract one, but we don't know how to write it in the place of the diamond sign. Is there a way to write it in the place of the diamond?

From, Maggie Hoyt and Robert Baskin.

Maggie and Robert have solved the problem but admit they don't see how to write it. Writing out the solution so somebody can understand it can sometimes be the hardest part of problem solving.

Also, note that these are fifth-graders. If you know algebra, you know other ways of describing the solution. How would you explain it to a fifth-grader? Or are there any other fifth-graders out there with a way to describe the solution?

Maggie and Robert also sent in a solution to Mystery Op 1. See what you think!

Send your solutions to You can even send another solution to this same problem if you'd like!

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