額 (Kanji for amount of money / forehead)

JERK- literally it means forehead, but as a jukugo it is a SUFFIX which means "amount of money."

Onyomi

GAKU	I got a fever, so I GOTTA COOL my forehead down with an ice pack.

Each customer's Head has a forehead (which we can polish for an amount of money) (forehead polishers Inc. - hot stock tip)

ひたい	forehead (BOOBOO: most people just say おでこ instead - different word, and not even written in kanji. So you can go ahead and ignore ひたい) BOOBOO ☆☆☆☆☆

半額(はんがく)

half-price ★★★☆☆
半 (half) + 額 (amount of money / forehead) = 半額 (half-price)

half-price, half the amount.

月額(げつがく)

monthly amount ☆☆☆☆☆
月 (moon) + 額 (amount of money / forehead) = 月額 (monthly amount)

the monthly amount of money

You ask a favor: that I give HEAD.

EACH of you asks for an amount of money.

So I shun you, I STOP talking to you.