Divisibility criteria Divisibility of numbers by 2, 4, 8, 3, 9, 6, 5, 25, 10, 100, 1000, 11. Divisibility by 2. A number is divisible by 2, if its last digit is 0 or is divisible by 2. Numbers, which are divisible by 2 are called even numbers. Otherwise, numbers are called odd numbers. Divisibility by 4. A number is divisible by 4, if its two last digits are … [Read more...]

## Laws of addition and multiplication

Laws of addition and multiplication Commutative laws of addition and multiplication. Associative laws of addition and multiplication. Distributive law of multiplication over addition. Commutative law of addition: m + n = n + m . A sum isn’t changed at rearrangement of its addends. Commutative law of multiplication: m · n = n · m . A product isn’t changed … [Read more...]

## Order of operations. Brackets

Order of operations. Brackets If brackets are absent, the following order of operations is right: 1) raising to a power and extraction of a root (one after another); 2) multiplication and division (one after another); 3) addition and subtraction (one after another). If brackets are present, at first all operations inside brackets are … [Read more...]

## Arithmetical operations

Arithmetical operations Addition (addends, sum). Subtraction (minuend, subtrahend, difference). Multiplication (multiplicand, multiplier, product, factors). Division (dividend, divisor, quotient, dividing integers, fraction, divisible numbers, remainder, division without remainder, division with remainder). Raising to a power (power, … [Read more...]

## Whole (natural) numbers

Whole (natural) numbers Natural numbers. Natural series. Integers. Natural numbers – numbers, which appear as a result of calculus of single subjects:peoples, animals, birds, trees, different wares and so on. Series of natural numbers: 1, 2, 3, 4, 5, … is continued endlessly and is called natural series. Integers – natural numbers and zero: 0, 1, 2, 3, 4, … [Read more...]