**25 Math Concepts you MUST know for the ACT!**

**Phil McCaffrey**

ACT Math – Top 25 ACT Math Concepts.

I read, analyze, and teach ACT Math problems 4 to 6 hours
per day, 5 days per week, sometimes more. Doesn’t sound like fun to anyone but
a real geek like me. But I love it, and I love helping the teenagers who come
to 3RPrep for help. When the SAT was
changing a few years ago, I convinced David to be my partner (because he is way
better at grammar than I am), and we painstakingly counted every “type” (or
concept) of question on the ACT. I just
looked at the list of math question types and tried to identify the ones that
are on almost EVERY test.

Stay tuned. I am going to make a very short lesson with an
example problem or two from every concept.

1.
Word Problems – 99% of the ACT math is word
problems. More, less, fewer, higher,
lower, double, half, etc.

2.
Properties of Integers. 90% + of the numbers
used by the ACT are integers. Even, odd, positive, negative, consecutive,
prime, factor, multiple, square, etc.

3.
Fractions. 1/a + 1/b = (a + b)/ab. 1/2 + 1/3 =
(2+3)/(2*3)

4.
Sequences. Arithmetic = add/subtract. Geometric
= multiply/divide.

5.
Ratio.
Part+Part=Whole.

6.
Rates & Proportions.

7.
Percent. Increase, decrease, percent of a
percent, interest.

8.
Algebraic Operations & solving equations.
Combine like terms – watch out for negative signs. Easy – don’t miss these.

9.
Algebraic Inequalities – graph them quickly.

10. Absolute
Value.

11. Exponents,
roots, logarithms.

12. Linear
Functions. ax+by=c & y=mx+b

13. Coordinate
Geometry in the xy-plane.

14. Systems
of Equations

15. Functions.
Evaluate f(x).

16. Quadratics,
parabolas, factor and FOIL.

17. Lines
& Angles. l is parallel to m, l||m

18. Triangles,
right, isosceles, 3-4-5

19. Quadrilaterals,
squares, rectangles, trapezoids.

20. Circles
& sectors. They love the angle of a piece of a pie chart.

21. Multiple
Geometry Figures. Big Area – Small Area is usually the answer.

22. Trigonometry.
Two SOHCAHTOA questions, usually straightforward.

23. Average,
Mean, Median, rarely mode.

24. Probability.

25. Counting,
Factorials, Permutations, & Combinations.

A new post almost 3 years later. So much has happened. I wonder if anyone will read this .

Tutoring is going well at 3RPrep (www.3rprep.com). We offer classes at schools and in our office, one on one tutoring in person and online.

Cheers

Phil