/learn/s18/t15930 /learn/node/43289 In lesson one, we explain the difference between analogue and digital quantities, analogue and digital measuring instruments, and how analogue data can be digitised so that a computer can use the data. We start by using examples with which learners will be familiar. These examples include temperature, speed and time. /learn/node/43290 In this third lesson, conversions using the binary and decimal number systems are discussed. In particular, learners are asked to compare “27” as two ASCII characters with the binary representation of “27” as a number. /learn/node/43291 In this lesson we use a pattern of numbers to generate a formula for working out the number of combinations for n bits. We also demonstrate how to convert decimal numbers to binary and using division to convert from binary to decimal numbers. /learn/node/43292 The focus of this lesson is on conversions using binary and hexadecimal number systems. The hexadecimal number system is often called “shorthand” for binary numbers and is easier to work with and write down. The worksheet designed for this lesson provides learners with two ways to convert from hexadecimal to binary. Learners can make a choice as to which of the ways they prefer when converting from hexadecimal to binary. /learn/node/43293 Lesson 5 deals with floating point notation, overflow, underflow and rounding errors. In this lesson we look at the representation of real or floating point numbers in a computer. The worksheet should be used to enable learners to become competent in writing numbers in scientific notation. Once they have mastered this skill, the video can be used to explain the link between scientific notation and floating point notation. In addition, we discuss why some calculation errors result in certain computer calculations. It is for this reason that choosing the type of data is important.