80+1= 81
81 = 8.1 x 101
81,000,000,000,000
81 = 92 or 8.1 × 101
There is no whole number - 81/90 in its simplest form is 9/10 !
81 is a whole number whose simplest form is 81.
81+0=81
Just writing "81" is mathematical enough for my taste. After all, that's a number, and numbers are mathematical.
80+1= 81
Without exponentsWith exponentsIn word form
81 = 8.1 x 101
81/100
No, -81 is not an irrational number because it can be represented in the form x/y = -81
Well, honey, if you want to write 0.81 repeating as a fraction in simplest form, you just gotta remember your high school math. It's 81 over 99, because that repeating decimal is 81 over 99. And if you want to simplify it, just divide the top and bottom by 9 to get 9 over 11. Voilà!
roughly 81 million.
9 to the power of 2 = 81
81,000,000,000,000