Integer Calculator

Integers are whole numbers, their negatives, and zero. They contain no fractional or decimal part. This integer calculator performs the four basic arithmetic operations on two signed integers: addition, subtraction, multiplication, and division. Entering negative values makes it useful for temperatures, account changes, elevations, game scores, number-line exercises, and any situation where quantities can move above or below a reference point. Addition combines quantities. When both integers have the same sign, add their absolute values and keep that sign. When their signs differ, subtract the smaller absolute value from the larger one and use the sign of the number with the larger absolute value. For example, negative 12 plus 7 equals negative 5 because the negative magnitude is larger by five. Subtraction can be understood as adding the opposite. Subtracting negative 4 from 9 is equivalent to adding positive 4, so the result is 13. This interpretation helps avoid memorizing separate sign rules and connects subtraction directly to movement on a number line. Parentheses are especially helpful when writing a negative second operand by hand. Multiplication follows a simple sign pattern. Factors with the same sign produce a positive product, while factors with different signs produce a negative product. Thus negative 8 times negative 6 equals positive 48, and negative 8 times positive 6 equals negative 48. Zero multiplied by any integer is zero. Division uses the same sign pattern, provided the divisor is not zero. Integer division does not always produce an integer. Twelve divided by 3 gives the integer 4, but 7 divided by 2 gives 3.5. The calculator displays the ordinary quotient rather than truncating it or reporting only a remainder. This behavior is useful when the goal is arithmetic evaluation. For quotient-and-remainder work, apply Euclidean division separately and specify the convention used for negative values. Division by zero is undefined because no number multiplied by zero can recover a nonzero dividend, and zero divided by zero has no unique answer. The calculator therefore rejects a zero divisor. Inputs must also be safe whole numbers so arithmetic remains deterministic in the browser. Decimal entries are not integers and are not accepted as operands. Order matters for subtraction and division but not for addition and multiplication. Swapping the two inputs leaves a sum or product unchanged, while it usually changes a difference or quotient. To check a result, use the inverse operation: add the subtracted value to a difference, multiply a quotient by its divisor, or divide a product by one nonzero factor. These checks provide a quick way to confirm signed arithmetic.