1)



[pic]

Are you ready to use your calculator?

Solve each problem on the calculator you plan to use when you take the MCA’s in math.

1) 34=

2) [pic] =

3) [pic]+[pic]=

4) [pic]

5) 3,500,000 x 27,500,000=

6) [pic]=

7) -5 – 12=

8) 3(-4 + 10)=

9) -42=

10) 30% of 240=

11) Acircle= (42 =

12) 2.5 million/5000=

MCA Calculator Use Teacher Notes

Overall message you want to give students: Just because you can get an ‘answer’ on the calculator, it doesn’t mean it is the correct ‘answer’.

1) Do students know how to enter exponents on their calculator? Depending on their calculator the button may look like… ^ or yx or something else. I also take this time to make sure students know how to work with exponents without a calculator. A really common question on the MCA (sometimes with a calculator and sometimes not….) is…

61, 32, 23, 17

Which shows the numbers ordered from least to greatest?

A. 17, 23, 32, 61

B. 17, 61, 23, 32

C. 61, 17, 23, 32

D. 61, 32, 23, 17

2) This is a common one that students do wrong on calculators….many students will enter 60-20÷4= and incorrectly get 55. The fail to realize that many calculators apply the order of operations. The correct solution should be 10 – so talk to your students about how you can get this on the calculator. Talk about implied parentheses….etc. You also may need to talk about the fact that the fraction bar represents division. Don’t assume all student know this.

3) FRACTIONS! Do your students know how to work with fractions on their calculator? I know many of you would like all students to have a calculator that does fractions easily (casio FX-55 for example), but many of them don’t have a calculator that does this easily, so you need to give ALL students ways of dealing with fractions on all calculators. In HS, your students will pretty much using a graphing calculator – that does not work like a FX-55, it is time to start this transition. I recommend talking to students about fraction bars representing division and how to convert fractions to decimals and back. If you are not sure how to do this on a graphing calculator – just ask.

4) Mixed Fractions….give student’s ways of thinking and working with these as well. (By the way – Several years ago I started having students memorize the decimal equivalent of 20-30 fractions {[pic], [pic], [pic], [pic], [pic], [pic], [pic], [pic], [pic]…eighths, tenths…they reported that this made tests like this easier…)

5) Converting from standard notation to scientific notation. Scientific notation looks different on different calculators. Many students want to ignore the x1013 part and just write down the 9.625 part of the solution. Talk to students about how to deal with really small and really large numbers and what this looks like on the calculator. You also may need to have a conversation about the commas in these numbers – there are still students that think you enter commas into your calculator.

6) Square roots…where are they on your calculator? Depending on the calculator it may work differently. Some calculators require students to type in 25 and then hit the square root key and some calculators (like the TI-84’s) require you to hit a ‘control’ or ‘2nd key’ first then hit the square root key and then enter 25. (note: I have students memorize all the perfect squares from 12 to 122 and backwards all the square roots of 1, 4, 9, 16, 25….121, 144 – these tend to be the only ones asked on most exams)

7) Do your students know the difference between a negative symbol and a subtraction sign and when to use which? I find a lot of students get error messages on their calculators due to confusion about this. Also, negative keys on calculators look different…some are (-) ….some are +/- …..and more, make sure students know how to use their own calculator.

8) Use #8 to talk to students about the various ways multiplication can be represented. Notice I also used a ‘traditional’ multiplication in problem #5 and in this problem multiplication is shown with parentheses…make sure you talk to students about the many forms of writing multiplication. You also can talk to students about how to enter parentheses on their calculator – this is not obvious to all students.

9) Squaring negatives can cause problems – depending on what you mean – check out this 8th grade test released item…

Evaluate 3x2+5x-4 when x=-3

A. -46

B. 6

C. 8

D. 38

Many students (especially using graphing calculators) do this problem incorrectly by entering 3•-32+5•-3-4 and get -46….why? the calculator only squares 3, not negative 3…to do this correctly students need to enter…

3•(-3)2+5•-3-4…notice the parenthesis….

10) Percents….how do you enter these on calculators. Use this as another opportunity to talk to student about entering (incorrectly) 4% as .4

11) How do you deal with pi? Almost every, if not every, problem on the MCA exam that involves pi includes a statement that looks something like this….(use 3.14 for π). The test HIGHLY recommends using the decimal approximation for π. I tell students they must use 3.14 and not use the π key on many calculators. This may seem like a small thing to us math teachers, but to some students the difference between 50.24 (using 3.14) and 50.26548246… (using the π button) is HUGE.

12) What do students do when they run into words like ‘million’ on the test. Many students have will inaccurately enter this because when they hear ‘million’ they think 6 zeros and enter 25,000,000 (or 25 million) incorrectly – be careful of this, it is on almost every exam – imbedded in some word problem like….A town of 2.5 million people want to divide themselves into 5000 groups. How many people will be in each group?

[pic]

Using the Calculator on the MCA Names_______________________

_______________________

▪ Go to

▪ Select “Graphing Calculator”

Scientific Mode

Use the scientific calculator to answer the following questions.

1) a) Abs(-5) = b) Abs (8) = c) Abs (-15) =

2) What does the “Abs” button do?

3) a) 3 x^y 2 = b) 2 x^y 4 = c) 4 x^y 2 =

4) What does x^y do?

5) Use the keys on the calculator to accurately simplify the following expressions.

a) (1.3 x 105) · (2.4 x 10-8) =

b) (1.44 x 107) ÷ (1.2 x 10-3) =

c) [pic]=

d) [pic] =

Graphing Mode

Use the graphing calculator to answer the following questions.

Graph each equation separately, sketch the graph, and tell whether it is linear or nonlinear.

6) [pic] 7) y = x2 + 4 8) y = -3x + 2

9) y = x4 – 6 10) [pic] 11) 2x – 3y = 8

Enter the following equations and use the “table” function to create a table of values for the following equations. Use the domain -2, 0, 2.

12) y = -4x + 7 13) -6x + 2y = 12 14) y = -3x2

Solve the system of equations by graphing two equations at a time. Make a sketch. Find the point of intersection. HINT: use the “Trace” option to find the solution.

15) x + 2y = 4 16) y = x 17) x – 4y = 10

x – y = 1 y = 8 –3x 2x + y = 2

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download