Without knowing the total number of shares, it's impossible to know what your friend's 10k shares would be worth. e.g. if there are 100M shares total, then his shares would be worth 10k/100M = 0.0001 of the valuation of $70B, i.e. $7M. In order to own these shares, he would have to exercise the options, meaning he would need to pay the strike price of $0.01 per share, i.e. 10k * $0.01 = $100.

Also important to note is the tax treatment of these shares. Depending on the jurisdiction, it's possible that he would be taxed on the value of these shares when they are exercised, and not when they are sold. In the example above, that would mean that he would owe taxes on $7M whenever they were exercised.

Check out something like https://smartasset.com/investing/how-do-stock-options-work or https://www.holloway.com/g/equity-compensation for more info. (I just found these by googling [guide to stock option compensation].)