Home

Maths

Measurement

Length: Comparing, adding and subtracting

Length: Comparing, adding and subtracting

Videos

Summary

Exercises

Select Lesson

Statistics

Bar charts

Pictograms

Tables

Geometry - properties of shapes

2D shapes: Types and properties

3D shapes: Types and properties

Right angles, acute and obtuse angles

Horizontal and vertical lines

Identifying parallel and perpendicular lines

Measurement

Length: Comparing, adding and subtracting

Mass: Comparing, adding and subtracting

Volume: Comparing, adding and subtracting

Adding and subtracting money

Telling the time

Comparing times

Units of time

Perimeter of rectilinear shapes

Fractions

Counting in tenths

Fractions of a set of objects

Fractions as numbers

Comparing unit fractions

Add and subtract fractions: Same denominator

Equivalent fractions

Rounding decimals

Comparing decimals

Multiplication and division

Counting in multiples of 4, 8, 50 and 100

Multiplying and dividing by 2, 3, 4 and 8

Multiplying a 2-digit number by a 1-digit number

Multiplication scaling problems

Dividing a 2-digit number by a 1-digit number

Correspondence problems

Addition and subtraction

Adding numbers using mental maths

Using column addition to add numbers

Subtracting numbers using mental maths

Using column subtraction to subtract numbers

Number and place value

Numbers to 1000

Place value: Three-digit numbers

Representing numbers in different ways

Explainer Video

Tutor: Alice

Summary

Length: Comparing, adding and subtracting

​​In a nutshell

Length is how you describe how long an object is compared to another. You can compare the sizes of objects using length and for small enough objects you can use a ruler to measure this.



Comparing length

Bigger objects have bigger lengths, so a 20cm20cm20cm​ fork is bigger than a 5cm5cm5cm​ eraser. Remember that you can only compare lengths if they have the same unit; an 11cm11cm11cm pencil is not longer than a 2m2m2m​ table! Use this equation to convert between units:


​100cm=1m=0.001km100cm = 1m = 0.001km 100cm=1m=0.001km



Adding and subtracting length

procedure

1.
Make sure the units are the same.
2.
Identify what the question is asking you:
  • "Find the total length of ..." means summing the lengths.
  • "How much longer is ..." means subtracting one length from the other.
3.
Convert the answer back into appropriate units (if required).



Example

How much longer is a 1.2m1.2m1.2m​ table compared to a 65cm65cm65cm​ chair?


​1.2m=120cm1.2m = 120cm1.2m=120cm

120−65=55cm‾120 - 65 = \underline{55cm}120−65=55cm​

​

Read more

Learn with Basics

Learn the basics with theory units and practise what you learned with exercise sets!
Length:

This is the current lesson and goal (target) of the path

Length: Comparing, adding and subtracting

Unit 1

Length: Comparing, adding and subtracting

Final Test

Test reviewing all units to claim a reward planet.

Create an account to complete the exercises

FAQs - Frequently Asked Questions

What happens when you use units of different length to measure with?

The size of the unit used to measure something affects the measurement. If you measure the same quantity with different units, it will take more of the smaller unit and fewer of the larger unit to express the measurement.

Which units of length are appropriate when measuring longer objects?

Objects larger than 10 mm but smaller than a metre should be measured using centimetres, and objects larger than a metre should be measured using metres. Very large distances should be measured in units of kilometres.

What units are used to measure length?

A kilometre (km), metre (m) and centimetre (cm) are the commonly used units of length.

©2020 - 2024 evulpo AG

Beta