How do you write 400000 in standard form?

Oh, that's a happy little question! To write 400,000 in standard form, we simply move the decimal point five places to the left because there are five zeros in 400,000. So, in standard form, 400,000 is written as 4 x 10^5. Just like painting a beautiful landscape, it's all about following the right steps with a touch of joy and creativity!