1 steak costs $9.99
2 steaks cost 2*9.99 = $19.98
This is before tax is applied
Apply the 6% tax to get
6% of 19.98 = (6/100)*19.98 = 0.06*19.98 = 1.1988
which rounds to 1.20 (rounded to the nearest penny)
The sales tax is therefore $1.20
Add this to the previous total (19.98) and we get a grand total of 19.98+1.20 = 21.18 which is the final cost (with tax included)
note: we can multiply 19.98 by the value 1.06 to get 19.98*1.06 = 21.1788 and that rounds to 21.18; so it's a different route to the second answer