Show work when multiplying 3.9*5.3

I use the expansion distributive thing

remember a (b+c) = ab+ac

3.9=4-0.1

3.9 times 5.3=

(4-0.1) times 5.3=

5.3 (4-0.1) =

5.3 (4) + 5.3 (-0.1) =

(5+0.3) 4+5.3 (-0.1) =

20+1.2-0.52=

20+0.68=

20.68

taht's one way