Chapter 8: Units, perimeter, area, volume and time

By the end of this chapter you will be able to

• Convert between metric units of length, mass and capacity by multiplying or dividing, and move the decimal point correctly
• Use approximate imperial equivalents (inches, pounds and pints) and say when an answer is an estimate
• Find the perimeter of rectangles and composite rectilinear shapes, working out any missing sides
• Find the area of rectangles and squares in square centimetres and square metres, and estimate the area of an irregular shape
• Find the volume of a cuboid by counting 1 cm cubes in layers, and understand that 1 ml = 1 cm³
• Convert between hours, minutes, seconds, days and weeks, including decimal amounts of hours
• Solve problems with measures and money using all four operations, including scaling a recipe and sharing equally

You should already know

• Multiplying and dividing whole numbers and decimals by 10, 100 and 1,000 (Chapters 4 and 5)
• Place value and the decimal point, including tenths, hundredths and thousandths (Chapter 7)
• Multiplying and dividing by one- and two-digit numbers (Chapters 4 and 5)
• Measuring and comparing lengths, masses and capacities in Year 4

Where this leads

• Converting between metric and imperial units more precisely, and miles and kilometres (Year 6)
• Area of parallelograms and triangles, and volume of cuboids using formulae (Year 6)
• Using formulae and rates to solve problems with measures (Year 6)