Numerals have a gender and agree with a noun in gender.
The masculine numerals from 3 to 10 (inclusive) are formed from feminine numerals by adding a suffix ה. (So for numerals the suffix ה is a sign or masculine gender what is reverse to nouns and adjectives).
The numbers from 3 to 10 are usually put before a noun. In this case the numeral may be put in a conjugate form (that is for the masculine form ה is sometimes replaced with ת).
The numerals 30, 40, …, 90 are formed adding the suffix ים to the numerals 3, 4, …, 9.
A noun greater than 9 with a numeral may be either single or plural. For numerals 1, 2, …, 9 the noun is in plural.
The numerals 11, 12, …, 19 are formed adding the word “10” after a numeral 1, 2, …, 9. The word “10” here is עשר for masculine and עשרה for feminine.