SO align input and submit

HTML

<form name="subscription" method="post">
                        <span><input type="number" value="1" min="1" max="100" id="serves_metric" />
													<input type="button" onClick="Metric_calc()" Value="Calculate" /></span>
                    </form>

CSS

input[type="number"]{font-family:'Open Sans Condensed', sans-serif;font-size:14px;font-weight:700;color:black;border:1px solid #141414;border-radius:0;height:25px;margin:0;}
input[type="button"]{font-family:'Open Sans Condensed', sans-serif;font-size:14px;font-weight:700;color:white;background-color:#141414;border:0;border-radius:0;height:25px;margin:0 0 0 -4px;transition-duration:0.4s}
input[type="button"]:hover{color:white;background-color:#3399ff;cursor:pointer}