I would write 0.61 as sixty-one hundredths. Or sixty-one pence in British money.
0.61 = 61/100
The word "next" can be put in front of "step" to form the phrase "next step."
four tenths
Three tenths.
Twenty-five.
5.864 in word form is: five and eight hundred sixty-four thousandths.
Thirty-six hundredths.
three and one tenth
Nine hundred twelve.
Thirty-four thousandths
One hundred an twenty
thirteen and eight tenths