There is no escape...believe it or not. Mathematics is everywhere.
What about songs?!
......have you heard the circle song?!
This makes me laugh every time I hear it! I once met some students singing it the day I first played it to them in a lesson.
....and at my school everybody knows about the area of a trapezium thanks to a little song!
In all of this I think we have to remember that we are all different - us and the children we teach.
No doubt that the understanding is the most important but then for some those mnemonics can help them remember things for exams which can be stressful. If a mnemonic helps them then so be it!
I find it is actually useful to discuss how we are going to remember key points with a class when we have completed something. If I ever tell them about some mnemonic I know about we then find out who it helps!
In my experience for any given mnemonic, some will find it helpful whilst it does nothing for others in the same class.
Instead of PEMDAS we use GEMS - Groupings, Exponents, Mult/Div, Add/Subt.
For integer addition, we sing to the tune of Row, Row, Row Your Boat:
Same Signs add and keep.
Different Signs subtract and
keep the sign of the higher number.
Then it will be exact.
I created a Glog (online interactive poster) for integer addition that you can see here: http://willkimbley.glogster.com/Integer-Addition/
For integer subtraction, we use Keep, Change, Change then follow the rules for addition.
So, for (-5) - (-7) = we perform the following steps
Keep Change Change
-5 - -7
| | |
-5 + 7
then follow the rules for addition, (different signs subtract) so rewrite and solve the problem:
7 - 5 = 2
the sign of the higher number (7) is positive, so the answer is positive 2