The number 90 is spelled "ninety." It is formed from its base of nine followed by a -ty which signifies that the number is followed by a tens placeholder.
Know MoreThe number 90 is often misspelled because many people drop the "e" and leave the word as "ninty."
Numbers between 20 and 100 that are multiples of 10 are spelled from a form of the base number followed by the -ty: twenty, thirty, forty, fifty, sixty, seventy, eighty and ninety. For the numbers between them, simply append the spelled number in the ones place to the spelled number in the tens place. For example, to spell 47, simply add "seven" to the end of the spelled number forty to get "forty-seven."
Learn more about NumbersThe number one is neither prime nor composite. Prime numbers are positive integers greater than one that are evenly divisible only by themselves and one. Composite numbers are positive integers that have divisors other than themselves and one.
Full Answer >A number that is multiplied by itself is called a base when it is written in exponential notation. Exponential notation consists of the number to be multiplied and a numeral in superscript to the right of it to indicate the number of times it is to be multiplied by itself.
Full Answer >The number 121 is not a prime number. A prime number must have only two factors, 1 and the number itself. However, the number 121 has three factors as 11 is a also factor of 121 in addition to 1 and 121 itself.
Full Answer >The number 37 is a prime number. The definition of a prime number is any positive number that can only be divided by the number one or itself. A prime number must also be a whole number larger than the value of one.
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