How do you write an algebraic expression for the word phrase “a number b divided by 8”?

Hint: Here in this question, we have to read the question and find the relation by reading the question. By knowing the relation, we can have to write in the form of numerals. While writing in the numeral form we use the variables, constants and arithmetic operations.

Complete step-by-step solution:
The algebraic expression or equation is a combination of variables and constants. The variables are alphabets and the constants are numerals. In the algebraic expression we have 3 different types and they are monomial, binomial and polynomial. The algebraic expression or equation involves the arithmetic operations.
We have some sentences, by reading the sentences we have to use arithmetic operations.
 If the sentence involves a plus b, the sum of a and b, a increased by b, b more than a, the total of a and b, b added to a then we use the addition arithmetic operation.
If the sentences involve a minus b, the difference of a and b, b subtracted from a, a decreased by b, b less than a then we use the subtraction arithmetic operation.
If the sentence involves a times b, the product of a and b then we use the multiplication arithmetic operation.
If the sentence involves a by b, the ratio of a and b, a is divided by b then we use the division arithmetic operation. And so on.
Now let we go through the question, in the question we have “a number b is divided by 8”. In this sentence we have divided words so we use division symbols.
Here we have a number b is divided by 8 it is written as \[b \div 8 = \dfrac{b}{8}\]
Therefore a variable expression for the word phrase “a number b is divided by 8” is \[\dfrac{b}{8}\]

Note: The algebraic expression or equation can be converted or transformed into a phrase form. The phrase form is converted or transformed into the numeral form. While converting or transforming the phrase form into numeral form we use variable, numbers and the arithmetic operations.