Multiply by Vedic method -

4.5 x 4.5

Method:

There are two sides of a product.

Left Hand Side = Multiplicand – 1

Right Hand Side = Multiplier – Left Hand Side

So, Multiplicand × Multiplier = Multiplicand – 1/ Multiplier – Left Hand Side

4×(4+1)/.5×.5

=20/.25

Ans: 20.25