Maths Unit 5 – Written Calculations Rounding to a given decimal place Grid multiplication Bus Stop method dividing 35 x 26 = To divide complex numbers, use the bus stop method. The number you are dividing by goes on the outside of the bus stop. To multiply complex numbers, partition the numbers and complete a multiplication grid. Rounding to a given decimal place Use the model below to help you multiply and divide numbers by 10, 100 or 1000. Place your number in the grid and follow the rules. Substitution Key words and definitions Rounding – the process of replacing the number by the nearest with a certain amount of decimals or significant figures Significant figure – each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first non-zero digit. Estimation – a rough calculation used to find the value of something by rounding all the component numbers to one significant figure.