Learn Farsi: این کت سیاه شصت و چهار تومان است.

In Farsi, compound numbers above twenty are made by joining the tens and the units with the word for and, which is و. So شصت و چهار translates literally to sixty and four. In everyday speech, that و is pronounced like a short o sound, making the number sound like shast-o-chahaar.

Since the price is sixty-four tomans, shouldn't the word تومان have a plural ending?

In English we say tomans, but in Farsi, you almost always use the singular form of a noun after a number. Because you already specified the quantity with شصت و چهار, adding a plural ending to the noun is not needed.

Why is the order کت سیاه instead of black coat like in English?

In Farsi, descriptive adjectives come immediately after the noun they describe. Also, remember that they must be connected by the Ezafe, an invisible short e sound added to the end of the noun. Because of this, you pronounce this phrase as kot-e siyaah.

The word شصت sounds a lot like the words for eight and eighty. How can I avoid mixing them up?

It is a very common trap! شصت (shast) means sixty. It helps to remember that the Farsi word for six is شش (shesh). Both sixty and six start with the sh sound. On the other hand, eight is هشت (hasht) and eighty is هشتاد (hashtaad), which both start with an h sound.