What is the value of 4 × 0.4 × 0.04 × 0.004 × 40?

Correct option is C

Given:

Mathematical expression: 4 × 0.4 × 0.04 × 0.004 × 40

Formula Used:

When multiplying decimal numbers we multiply the numbers ignoring the decimal and after multiplying we count the number of decimals in the numbers and put the decimal in our result.

Solution:

Here, after ignoring the decimals expression will become:

=  4 × 4 × 4 × 4 × 40 = 10240

Counting the number of decimals in expression:

4 × 0.4 × 0.04 × 0.004 × 40 = 6 decimals

The final number will have 6 decimal places;

= 0.010240

= 0.01024