## Friday, February 09, 2018

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
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