Redux actions inside a container for a calculator
I would try to extract some of the common functionality into reusable components as follows. The NumericButton and OperatorButton components could either receive selectNumber and selectOperator as props or the components could be connected components with the select* props coming from mapDispatchToProps. The connected component method eliminates the need to pass the prop in every component instance in ButtonContainer, but increases the number of connected components thus adding some complexity.

const CalculatorButton = ({ children, className, onClick, value}) =&gt; {
  return &lt;button value={value} onClick={e =&gt; onClick(e.target)} className={`buttonStyle ${className || ''}`} type="submit"&gt;{children || value}&lt;/button&gt;;
};

const NumericButton = ({ className, value }) =&gt; {
  return &lt;CalculatorButton className={className} onClick={selectNumber} value={value} /&gt;;
};

const OperatorButton = ({ className, value }) =&gt; {
  return &lt;CalculatorButton className={className} onClick={selectOperator} value={value} /&gt;
};

const ButtonsContainer = () =&gt; (
  &lt;React.Fragment&gt;
    &lt;CalculatorButton className="ac" onClick={() =&gt; initialize()} value="AC" /&gt;
    &lt;CalculatorButton className="ce" onClick={() =&gt; clearEntry()} value="CE" /&gt;
    &lt;CalculatorButton className="posneg" onClick={changeSign} value="CHANGE"&gt;{'+/-'}&lt;/CalculatorButton&gt;
    &lt;OperatorButton className="divide" value="/" /&gt;
    &lt;NumericButton className="seven" value="7" /&gt;
    &lt;NumericButton className="eight" value="8" /&gt;
    &lt;NumericButton className="nine" value="9" /&gt;
    {/* etc. */}
  &lt;/React.Fragment&gt;
);