  # Order of Operations Activities

Written by Tom Fanning
November 01, 2010

The unit in the 7th grade Computers course is called Combining Practice. These activities involve solving math puzzles in an Excel spreadsheet, collaborative writing on what you know about the rules for order of operations, and a quick self-grading activity to indicate students’ current level of understanding of order of operations.

The Combining Practice puzzles introduce students to writing formulas and functions in Excel. The challenge is to combine the numbers, like 1, 2, and 3, in such a way as to make the result come to each of the values of zero to ten. For example, in Excel, to make the value come to zero, the formula is “= 1 + 2 – 3”.

Students work with a partner on this puzzle. This activity is easy to explain to students and it’s easy for them to start solving. But to complete all the entries is difficult. All parts of this puzzle have a solution, but some parts require complex formulas which include built-in Excel functions. For example, to get 8 using only 3, 6, and 9, Angela and Sabina entered:

=ROUNDDOWN(SQRT(AVERAGE(9, 3)), 0) +6.

Here are the puzzle solutions submitted by two different partnerships:

(Note: Click on the link, choose Save. After saving, click Open.)

AngelaSabinapuzzle.xls

marshalldannypuzzle.xls

Prewriting occurred when students were asked to submit a Word document containing two paragraphs. Paragraph one was to explain what the rules of order of operations are, and paragraph two was to explain why we need these rules in the first place. The purpose of this activity is to get students writing in detail about the process and to step back and consider why mathematicians worldwide accept these rules for simplifying expressions.

Here is the writing sample of one partnership: The final activity leading up to making the video was to have each student rate their own knowledge of order of operations. This was done simply by checking the option that best fit each student’s situation.

Click on the link below to view how Marshall rated his understanding of order of operations.