how do you write 25.4 millimeters in scientific notation

2.54x10 to the 1st power because you take the first number you see to the left, place the decimal behind it, write the other numbers behind it (don't include 0s unless the 0 has a number above 0), multiply by 10, and to figure out the exponet, you just count how many spaces the decimal moves. If the decimal moves to the right then the exponent is positive, of you move it to the left then the exponet is negative.