A standard lot is 100,000 units of an instrument so 0.01 lot is (0.01 x 100,000 units) = 1,000 units
Now if you are trading an instrument like eur/usd with an exchange rate of say 1.1393 then 0.01 lot will be worth (1,000 units x 1.1393) = $1,139 USD
But you don't need to put down this full amount of $1,139 before opening a trade, if you are using a leverage of say 1:400 then you only need to put down ($1,139 /400) = $2.85, to open a trade.
Now, $2.85 is the value of 0.01 lot size when you are using 1:400 leverage, so if you convert $2.85 to South African Rand that will give you around 50 Rand.
