Suhdeluvut

Suhdeluvut are a fundamental mathematical concept that expresses the relative size of two quantities. In its simplest form, a suhdeluku is the quotient of two numbers a and b (with b ≠ 0), written as a/b, or as a:b in colon notation, or as a percentage after multiplying by 100. They capture how many units of one quantity correspond to one unit of another.

They are dimensionless and depend only on the relation between the quantities, not their absolute size. If two pairs (a, b) and (ka, kb) share the same suhdeluku for any nonzero k, the ratio is considered the same. The ratio can be simplified by dividing both parts by their greatest common divisor, yielding a in lowest terms. Equality a:b = c:d holds when ad = bc.

To compare ratios, cross multiplication is commonly used. Ratios do not generally add directly; instead, they are combined in proportions or converted to fractions or decimals for arithmetic. Converting to percentages is a common way to express ratios as a relative part of a hundred.

Suhdeluvut appear in many contexts, including recipes, maps, finance, and statistics, where they express rates such as speed, density, or probability. Example: the ratio 3:4 means that for every 3 units of the first quantity there are 4 units of the second.