title: Adding and subtracting within a range of numbers and looping round
body: <p>I'm wondering how I would go about the addition and subtraction of numbers in a set range and which would loop back on themselves, example below;</p>
  
  <p>Range: 1 - 10</p>
  
  <p>So if I now had the number 7 and added 5 to it, I would want the number go to 2</p>
  
  <p>8, 9, 10, loop around to 1, 2.</p>
  
  <p>And the same if I subtracted, so I have the number 3 and I subtract 4 so I should be left with 9.</p>
  
  <p>2, 1, loop around to 10, 9</p>
  
  <p>I hope this makes sense.</p>
  
  <p>Thanks.</p>