I heard the apostle of Allah ﷺ say: A man returns after saying his prayer while a tenth part of his prayer, or a ninth part, or an eight part, or a seventh part, or a sixth part, or a fifth part, or a third part, or half of it, is recorded for him.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ إِنَّ الرَّجُلَ لَيَنْصَرِفُ وَمَا كُتِبَ لَهُ إِلاَّ عُشْرُ صَلاَتِهِ تُسْعُهَا ثُمُنُهَا سُبُعُهَا سُدُسُهَا خُمُسُهَا رُبُعُهَا ثُلُثُهَا نِصْفُهَا