To express 0.0004 as a percentage, you need to multiply it by 100. This is because the term ‘percentage’ means ‘out of 100’. Hence, when you multiply, you convert the decimal into a fraction of 100.
So, the calculation would be:
0.0004 × 100 = 0.04
This means that 0.0004 expressed as a percentage is 0.04%.
In summary, whenever you want to convert a decimal to a percentage, just multiply by 100 and add the percent sign (%). That’s all it takes!