Mathematical Processes and Number Sense
This domain tests both your number fluency and your habits of mathematical reasoning. You should be comfortable with the real number system and its subsets (natural, whole, integer, rational, irrational), with the properties of operations (commutative, associative, distributive, identity, inverse), and with the order of operations. Expect questions on place value, scientific notation, absolute value, factors and multiples, prime factorization, GCF and LCM, and operations with fractions, decimals, and percents. Proportional reasoning is central: setting up and solving proportions, unit rates, and percent change.
Traps are common here. A frequent one is confusing GCF with LCM, or applying the distributive property incorrectly across a negative sign. Another is percent change versus percent of: a 20% increase followed by a 20% decrease does not return to the original value. Watch for questions that hinge on whether zero is included in a set, or on the difference between rational and irrational numbers (recall that repeating or terminating decimals are rational).
Rule of thumb: When a problem involves rates, write the units into the proportion and cancel them; if the units don't cancel to the desired unit, invert the ratio. For example, to convert 45 miles per hour to feet per second: 45 mi/h × 5280 ft/1 mi × 1 h/3600 s = 66 ft/s. The unit labels confirm the setup.
Also practice justifying your reasoning, since process questions may ask which property or strategy is valid rather than for a numeric answer.