Arithmetic and Algebra Flashcards
(16 cards)
What is the most common algebra trap?
DOING THE MATH!
See if there is an alternative method
Transform algebra from unknowns with…
real numbers. Mentally easier
What is the verbiage signal for testing cases?
“must be” or “Could be”
Design cases with the intent of disproving answers
What are the signals for “smart numbers”?
- When given unknown values
- When given relative values
- “find a variable expression”
What is the appropriate smart number when given a percentage?
100
What are the signals to “work backwards”?
- The answer represents a single variable as an actual value. Can be plugged in
What is the step in “working backwards” when you’re about to pick an answer choice to attempt?
Selecting either B or D! If B is too low, test D… if D was too high it must be C. If D is still low, than the answer is E
Tips when testing cases…
- Test enough valid cases to prove definitively an answer
- Start with small integers such as 1 or 0
- Test weird properties like negatives, primes and fractions
What would be ideal in testing a case with…
1. Abs value
2. Exponents
- negative
- Fractions
Rules with “smart numbers”
Different than testing cases
- Stick to normal, easy values.
- Avoid 0 or 1
- Avoid numbers that appear in problem or repeats in general
What is a good start number when given a fraction…
a lowest common denominator
What is a good start number when given a ratio…
steal the ratio!
What is a good start number when told to divide or do a Rate/work word problem with…
a multiple of the divisor value that will yield an integer
What is a good start number when given a variable underneath a radical…
An even square
If an unknown value is indirectly asked for or referred to in the question…
pick a smart number following the same rules.
exp. all employees are paid the same hourly wage
If the question says pick the lowest value out of a pair, and you observe the pair in the answer choice…
Work backwards ONLY with the lowest value, since obviously the greater value would be rejected due to the Q stem criteria