How to multiply any number with decimal number

Question

I can't remember multiplication tables, is there any math trick for multiplication?

Answer 1

Basically you count the number of decimals,

Consider $$45.2 \times 2.34$$

You do $$452 \times 234 = 105768$$

Notice how 45.2 has a decimal "one place" to the right, and 2.34 has a decimal "two places" to the right. Adding them up, we get "3 places to the right", for a final answer of $105.768$

Answer 2

Just do simple multiplication of numbers and place the decimal on the correct position
For Example:$$2.3\times5.18$$ Step $1:\text{Simple multiplication}$ $$23\times518=11914$$ Step $2:\text{Place the decimal}$ $$=11.914$$