Year 5 · Units, perimeter, area, volume and time · Summary

Year 5 Units, perimeter, area, volume and time: summary and key words

Part of the Year 5 units, perimeter, area, volume and time chapter. Chapter overview · whole chapter on one page

Chapter summary

Skill	Method
Metric units	Smaller unit: multiply. Bigger unit: divide. 1 km = 1,000 m; 1 m = 100 cm; 1 cm = 10 mm; 1 kg = 1,000 g; 1 litre = 1,000 ml.
Imperial units (about)	These are approximate, so write about. 1 inch ≈ 2.5 cm; 1 kg ≈ 2.2 pounds; 1 litre ≈ 1.75 pints.
Perimeter	Add the lengths of all the outside sides. Find missing sides by subtracting a shorter side from a longer one.
Area of a rectangle or square	Length × width, in square units (cm² or m²).
Estimating area	Count the whole squares. Two part squares make one whole square.
Volume	Count the cubes in one layer, then multiply by the number of layers. The unit is cm³.
Capacity	1 ml = 1 cm³, and 1 litre = 1,000 ml = 1,000 cm³.
Time	1 hour = 60 minutes, 1 minute = 60 seconds, 1 day = 24 hours, 1 week = 7 days.
Problems with measures	Use the same unit, choose the operation, then check the size of the answer. To scale, find the amount for 1 first.

I can change between km and m, cm and m, cm and mm, g and kg, and litres and ml.
I can use the words about and ≈ with inches, pounds and pints.
I can find the perimeter of a rectangle and of an L-shape, including missing sides.
I can find the area of a rectangle or square in cm² or m².
I can estimate the area of an irregular shape by counting squares.
I can find the volume of a cuboid by counting cubes in layers, and use 1 ml = 1 cm³.
I can change between hours, minutes, seconds, days and weeks.
I can solve problems with measures and money, including scaling a recipe.

Perimeter: The distance all the way round the outside of a shape.
Area: The amount of surface inside a shape, measured in square units.
Square centimetre (cm²): The area of a square with sides of 1 cm.
Composite shape: A shape made from two or more simple shapes, such as rectangles joined together.
Rectilinear shape: A shape whose sides meet at right angles, such as an L-shape.
Volume: The amount of space a solid takes up, measured in cubic units.
Cubic centimetre (cm³): The volume of a cube with sides of 1 cm.
Capacity: How much a container can hold, often measured in litres or millilitres.
Imperial unit: An older unit, such as an inch, a pound or a pint. We use about when we change to metric units.
Duration: How long something lasts, such as 2 hours 30 minutes.