Decimal divisions, also known as decimal fractions, are a way of expressing fractions with a denominator of 10 or a multiple of 10. The term 'tenths' refers to fractions with a denominator of 10, such as 1/10, 2/10, 3/10, etc. These fractions can be written in decimal form, such as 0.1, 0.2, 0.3, etc. Decimal divisions are used in many areas of mathematics, including arithmetic, algebra, and geometry.