Simple Maths thats driving me Crazy

Little Background. I was trying to do more complex math's and was planing on using "hidden" inputs for each step, but i wanted to see what was going on while I was changing it, so am using a number thats "disabled" so that it works like a hidden, but that i can see whats going on to check its working. The number's where all coming out crazy and I am now totally confused. I Created a new sheet and reproduced my problem with the below; <span>Max Health </span><input type="number" name="attr_maxhealth" value="20" disabled="true" /><br />     <span>Current Health </span><input type="number" name="attr_currenthealth" value="@{maxhealth}-@{damagetaken}" disabled="true" /><br />     <span>Damage Taken </span><input type="number" name="attr_damagetaken" value="0" /><br /> <br /> <span>currentHealth (works)</span><input type="number" name="attr_test1" value="@{currentHealth}" disabled="true" /><br /> <span>14*14 (works)</span><input type="number" name="attr_test1" value="14*14" disabled="true" /><br /> <span>currentHealth*14 (doesnt)</span><input type="number" name="attr_test1" value="@{currentHealth}*14" disabled="true" /><br /> <span>currentHealth*currentHealth (doesnt)</span><input type="number" name="attr_test1" value="@{currentHealth}*@{currentHealth}" disabled="true" /><br /> <br /> <span>doubleSquare encased</span><br /> <span>currentHealth*14 (doesnt)</span><input type="number" name="attr_test1" value="[[@{currentHealth}*14]]" disabled="true" /><br /> <span>currentHealth*currentHealth (doesnt)</span><input type="number" name="attr_test1" value="[[@{currentHealth}*@{currentHealth}]]" disabled="true" /><br /> <br /> <span>doubleCurley encased</span><br /> <span>currentHealth*14 (doesnt)</span><input type="number" name="attr_test1" value="{{@{currentHealth}*14}}" disabled="true" /><br /> <span>currentHealth*currentHealth (doesnt)</span><input type="number" name="attr_test1" value="{{@{currentHealth}*@{currentHealth}}}" disabled="true" /><br /> <br /> <span>double BOTH! encased</span><br /> <span>currentHealth*14 (doesnt)</span><input type="number" name="attr_test1" value="[[{{@{currentHealth}*14}}]]" disabled="true" /><br /> <span>currentHealth*currentHealth (doesnt)</span><input type="number" name="attr_test1" value="[[{{@{currentHealth}*@{currentHealth}}}]]" disabled="true" /><br /> The top Two that are the simple get number and 14*14 are right and give 14 and 196 respectively, everything else gives either 64 or -100 (I think, It could be bigger but the box is too narrow) What am I doing wrong!

This is an order of operations issue. let's say you have max health 20 and damage taken 1. since current health is set to max health - damage taken, it's easy to think of it as "19", but it's actually "20-1", since roll20 evaluates attribute calls first and then does the math at the end. so current health * current health isn't "19*19", it's "20-1*20-1".  And since order of operations will resolve the multiplication before the subtraction, you'll end up with -1 when you expected a 361.

I think Alan has the correct diagnosis. The resolution will be to use parenthesis. Either around your `currentHealth` formula, or around `@{currentHealth}` when referenced in other formulas. <div>   <span>Current Health</span>   <input type="number" name="attr_currenthealth" value="(@{maxhealth}-@{damagetaken})" disabled="true" />   </div> <div>   <span>Damage Taken</span>   <input type="number" name="attr_damagetaken" value="0" /> </div> <div>   <span>currentHealth*currentHealth</span>   <input type="number" name="attr_test1" value="@{currentHealth}*@{currentHealth}" disabled="true" /> </div> -or- <div>   <span>Current Health</span>   <input type="number" name="attr_currenthealth" value="@{maxhealth}-@{damagetaken}" disabled="true" />   </div> <div>   <span>Damage Taken</span>   <input type="number" name="attr_damagetaken" value="0" /> </div> <div>   <span>currentHealth*currentHealth</span>   <input type="number" name="attr_test1" value="(@{currentHealth})*(@{currentHealth})" disabled="true" /> </div>

Legend! Thankyou both!