February 2022

WHAT ARE FORMULA CARDS? WHAT ARE THEY USED FOR? AND WHERE CAN I GET THEM?

Having been repeatedly threatened by my high school math teachers that I would be doomed to fail their tests if I did not memorize all those math formulas, I was somewhat surprised later in a college calculus course when the professor handed out “formula cards” containing over ninety geometry, trigonometry identities, and calculus formulas. He explained that they could be used on his tests.  He did not bat an eye as he handed them out and reminded us that selecting the correct formulas and knowing how and when to use them was far more important than trying to memorize them or write them on the desk top.

So, when I started teaching at the high school, I announced to the students that they could make “formula cards” by using 5 x 8 inch cards, lined on one side and plain on the other.  It never failed.  Immediately, one of the students would ask why I did not have them printed off and handed out, saving them a considerable amount of time and money creating their own.

I told my students that whenever they encountered a formula in their textbooks, writing it down would strengthen the connection more than if they just read it and tried to recall it later while working a problem.  Reading the formula in the textbook was their first encounter and there would not yet be a strong connection between what they were reading and what they tried to remember.  However, when they took the time to create a formula card for that particular formula, they would be strengthening that connection.  As they used the card when doing their daily assignments, they would continue the process and eventually place the formula in their long term memory.

So, how can you get formula cards?  Simple! Each student makes his own. I allowed my students to use them starting with Math 87 or Algebra 1/2.  One young lady in my Algebra 2 class used blue cards for geometry formulas and white cards for the algebra formulas to save her time looking through the cards.  The cards should be destroyed after completion of the course, requiring the next student to make his own.  Then how do you make formula cards?

Have the students use 5 x 8 cards – and write or print clearly and big.  On the plain side of the card they print the title of the formula such as the formula for the area of a sector found on page 16 of the third edition of the Algebra 2 textbook. Then, on the front of the card (the plain side) in the center of the card the student would print:

AREA OF A SECTOR

When you turn the card over, in the upper right hand corner is the page number of the formula to enable the student to immediately go to that page should he need more information (in this case page 18 in the 2nd Ed & page 16 in the 3rd Ed).  Recording the page number saves flipping through the book looking for the information and wasting time, especially when the student encounters a difficult problem some twenty lessons later.

After writing down the appropriate page number, they neatly record the formula: (double checking to make sure they have recorded it correctly.)

Area of Sector = Pc/360 times pi(r)2  –  Where Pc equals the part of the sector given.

NOTE:  If diameter is given remember to divide by two before squaring the value.

Remember, students may also use the formula cards on tests – and if you watch them – the dog eared cards seldom get looked at after awhile.

For those of you concerned about students taking the ACT or SAT, unless they have changed their policy, students are given a sheet of formulas for the math portion of the test.  Again, this requires the student to know which formula to select and what to do with it – rather than remembering all those formulas!