simple12.html

---
layout: base.html
title: Simple HTML - Random numbers
---
<section class="side-by-side">
	<canvas class="game right" id="canvas" oncontextmenu="event.preventDefault()"></canvas>
	<div>
	<article>
		<h1>Random numbers</h1>

<p>
When you throw dice it is hard to guess,
or predict, what numbers you will get.
Unpredictable numbers like these are
called random numbers.
Below you can find out how
to make a computer produce random
numbers. The command is quite
complicated, but it is useful
in all sorts of programs.
</p>

<pre>
PRINT INT(RND*10+1)
</pre>

<p>This produces a random number between 1 and 10.</p>

<h3>Displaying random numbers</h3>
<p>
	Here is a simple random
	number program to try. Line
	40 tells the computer to pick
	a number between 1 and 20
	and display it on the screen.
	Run the program a few
	times. The computer will
	pick a new number each
	time.
</p>
<pre>
NEW
10 CLS
20 PRINT "HERE IS A NUMBER"
30 PRINT "BETWEEN 1 AND 20"
40 PRINT INT(RND*20+1)
RUN
</pre>

<aside><p>You can also write <code>RND</code> as <code>RND(1)</code>. If you write <code>RND(0)</code> you'll actually get back the previous random number that was generated!</p></aside>

<h3>How does <code>RND</code> work?</h3>
<p>
To complete the instruction
you need to multiply by the
number of numbers the
computer can choose from,
and add the lowest number it can pick.
</p>
<p>
For example, to make the computer pick
numbers from 1 to 6, like a
dice, you need the
instruction below.
</p>
<pre>
PRINT INT(RND*6+1)
</pre>
<p>
<center><img src="{{ base_uri }}/img/usborne/simple-basic/img/12random.png"></center>
</p>
</article>
<article>
	<h2>Lucky draw program</h2>
<p>
	The monster gang are having a lucky draw.
	They have sold 30 tickets, numbered from 1
	to 30, and they want the computer to pick the
	winning number. The program below
	will make the cmputer do this, but it is not
	complete. See if you can <strong>fill in the missing
	numbers in line 20</strong>. This is the line that tells
	the computer to pick a random number
	between 1 and 30.
</p>

<pre>
NEW
10 CLS
20 W = INT(RND * ?? + ??)
30 PRINT "HELLO MONSTERS"
40 PRINT "THE LUCKY WINNER"
50 PRINT "IS NUMBER";W
RUN
</pre>
		<footer>
			<a href="{{ base_uri }}/simple13" class="button">Next</a>
		</footer>
	</article>
	</div>
</section>