You can do simple decimal calculation with out using a calculator once you understand the basic concept of decimals. In decimal equations when you have various operations between decimal numbers, you have to go by the order of operations in simplifying it. The order of operations states that you have to first divide, then multiply and at last add or subtract the remaining terms. You have to work the operations from left to right. Use a calculator only when you are required to multiply or divide complex decimal numbers. In this way you can follow the order of operations and solve decimal equations. In case you have fractions in the equation, it is better to work with the fractions while applying operations and only convert it into decimal in the last step. This video shows how to calculate decimal equations using calculator to the minimum.