戊
halberd (radical)
So, this is the radical for the 5th heavenly stem. To say 5 in Chinese is 五 /Wǔ/. If you can remember that the HALBERD 戊 is connected with 5, and that the pronunciation is falling 4th tone /Wù/ to differentiate it from the number, it might help. It helps me.
by
jillanne