Question

classify each number below as an integer or not.

	integer?
21.51	○	○
651.86	○	○
$-dfrac{2}{3}$	○	○
72	○	○
$dfrac{40}{5}$	○	○

Explanation:

Step1: Define integers

Integers are whole numbers (positive, negative, or zero) with no fractional/decimal parts.

Step2: Evaluate 21.51

Has decimal part → Not integer.

Step3: Evaluate 651.86

Has decimal part → Not integer.

Step4: Evaluate $-\frac{2}{3}$

Is a fraction → Not integer.

Step5: Evaluate 72

Whole number → Is integer.

Step6: Evaluate $\frac{40}{5}$

Simplify: $\frac{40}{5}=8$, whole number → Is integer.

Answer:

Number	Integer? Yes	Integer? No
651.86		✅
$-\frac{2}{3}$		✅
72	✅
$\frac{40}{5}$	✅