What is the best way to generate a random addition problem?

Posted on 2014-12-14
Medium Priority
Last Modified: 2014-12-15

What is the best way to generate a random addition problem in android on a textview using only numbers 1-9?

8 + 7 = ?
Question by:Computer Guy
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LVL 16

Expert Comment

ID: 40499153
Math.rand. No? Tried it?

Author Comment

by:Computer Guy
ID: 40499168
LVL 28

Expert Comment

ID: 40499180
You want something like this:

Random r = new Random() ;
int first       = r.nextInt(9) + 1 ; // 1-9
int second = r.nextInt(9) + 1 ; // 1-9

String problem = Integer.toString(first) + " + " + Integer.toString(second) + " = ? " ;

Now show 'problem' in the text view.

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LVL 25

Accepted Solution

Tomas Helgi Johannsson earned 2000 total points
ID: 40499200

To generate random number between 1 - 9 you can do this

Random rn = new Random();
int firstnum = rn.nextInt(9) + 1;
int secondnum = rn.nextInt(9) + 1;

Then simply present it using SetText method in TextView

I suggest you have a class that generates the math equation to solve and does the solving.

    Tomas Helgi

Author Comment

by:Computer Guy
ID: 40499223
Also how can I generate the answer?

I have 3 buttons below the question I need to generate 2 random numbers and the other button needs to be the answer.
LVL 16

Expert Comment

ID: 40499266
BTW I meant Math.random() - got my languages wrong. ;)
LVL 16

Expert Comment

ID: 40499388
I need to generate 2 random numbers

All you need is

int r_1 = (int)(Math.random()*10);
int r_2 = (int)(Math.random()*10);
int answer = r_1+r_2;

Open in new window

Java.util.Random is for streams of numbers. Doesn't look like you need that.

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