Присвоить переменной число из кнопки

[Pholko]

Вот код кнопки:
<button ng-click="trackEvent(&quoteposit&quot;, &quot;balance&quot; trackUniqueEvent(&quoteposit_click&quot;, &quot;success&quot; updatePeopleProfile(&quoteposit_click&quot;, &quot;now&quot; openDeposit()" class="balance-btn ng-scope" ns-popover="" ns-popover-template="new-deposit" ns-popover-angular-event="win-deposit" ns-popover-theme="ns-popover-tooltip-theme new-deposit" ns-popover-placement="bottom|center" ns-popover-timeout="360"><div class="balance-btn-left ng-scope" ns-popover="" ns-popover-template="balance-notification" ns-popover-angular-event="balance-notification" ns-popover-theme="ns-popover-tooltip-theme push-message balance-notification" ns-popover-placement="bottom|center" ns-popover-timeout="360" ng-class="{pending: pendingDeposits.count > 0}"><i class="icon-spt deposit"></i> <span id="user-balance"><span class="counter ng-binding">0.01406</span> mBTC</span></div><div class="balance-btn-right"><span><i class="icon-spt deposit-plus"></i></span></div></button>
меня интересует как присвоить число 0.01406 допустим переменной const??? в последующем это число будет сверяться с другим. как это написать на js?

[Pholko]

<button
ng-click="trackEvent('Deposit', 'balance'); trackUniqueEvent('Deposit_click', 'success'); updatePeopleProfile('Deposit_click', 'now'); openDeposit()"
class="balance-btn ng-scope"
ns-popover=""
ns-popover-template="new-deposit"
ns-popover-angular-event="win-deposit"
ns-popover-theme="ns-popover-tooltip-theme new-deposit"
ns-popover-placement="bottom|center"
ns-popover-timeout="360"
>

<div
class="balance-btn-left ng-scope"
ns-popover=""
ns-popover-template="balance-notification"
ns-popover-angular-event="balance-notification"
ns-popover-theme="ns-popover-tooltip-theme push-message balance-notification"
ns-popover-placement="bottom|center"
ns-popover-timeout="360"
ng-class="{pending: pendingDeposits.count > 0}"
>
<i class="icon-spt deposit"></i>
<span id="user-balance">
<span class="counter ng-binding">0.01406</span>
mBTC
</span>

</div>

<div class="balance-btn-right">
<span>
<i class="icon-spt deposit-plus"></i>
</span>
</div>

</button>

[Dilettante_Pro]

const = parseFloat(document.getElementsByClassName("counter ng-binding")[0].innerText);

- это если на странице один элемент с таким классом