What does a child have to do to compare bar-chart values in the 11+?

Compare two category values on a bar chart. It is one of 55 named maths skills in the 11+, in the data strand, and this page carries 1 interactive exercise that practises it.

What should my child be able to do before working on compare bar-chart values?

The skill map puts read a bar-chart value first. A comparison requires accurate scale reading. If compare bar-chart values keeps going wrong, that is the thing to check before doing more of this one.

What is the trap in an 11+ compare bar-chart values question?

Adding the two bars gives their combined total, not how many more one bar shows than the other. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.

What is not part of compare bar-chart values in the 11+?

The skill map draws the line here: One comparison or difference only. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.

Which other 11+ skills should we practise alongside compare bar-chart values?

The data strand holds 9 skills that are tested together, and the pages next to compare bar-chart values are compare line-graph change, compare table values and decode a pictogram key. Each has its own exercise and its own link, and none of them needs an account.

How can my child practise compare bar-chart values for free?

Use Bar Reader, embedded on this page. It is the exercise the skill map attaches to compare bar-chart values, it runs in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. It also has its own link, so you can send it to a child without sending them anywhere else first.

Maths · Data

Compare bar-chart values

Compare two category values on a bar chart.

Practise it now

Tap the Train bar. Then read its top off the scale: how many children does it stand for?

This exercise practises compare bar-chart values alongside its own main skill, Reading values off a bar chart.

Loading the interactive exercise. Nothing you do here is saved or scored.

A worked example

One question of the kind this skill is tested with, worked all the way through: the reasoning, and what the wrong answers are there to catch.

Passengers boarding at Fenbury Station

Compare the Caldale bar with the Ashford bar. How many more passengers does Caldale show?

Each bar shows the number of passengers recorded for that service.

Answer: 10

How you get there

Caldale reaches 20 and Ashford reaches 10, so 20 - $10 = 10$ , which means 10 more passengers are counted for Caldale.

Why the other answers tempt

Adding the two bars gives their combined total, not how many more one bar shows than the other.

If they are stuck, say this

Read the Caldale bar and the Ashford bar off the scale first, then take the smaller number away from the larger one.

Now do it live in Bar Reader

Kitchen-table script for parents

Try this together

A friendly mini script for the breakfast table, school run or a quiet two minutes. Read it aloud as written, or make it your own.

Ready? Let's have a go at Compare bar-chart values together. Take a look at the picture. Here is what matters: Bar chart with horizontal axis Service and vertical axis Passengers: Eastwick is 50; Caldale is 20; Fenwick is 35; Ashford is 10; Bridgend is 30. Here comes the question: Compare the Caldale bar with the Ashford bar. How many more passengers does Caldale show? Before we race ahead, let us choose one good first step. Here is a helpful clue: Read the Caldale bar and the Ashford bar off the scale first, then take the smaller number away from the larger one. Nice work. Now let us follow the thinking: Caldale reaches 20 and Ashford reaches 10, so 20 - 10 = 10, which means 10 more passengers are counted for Caldale. So our answer is: 10. There is one sneaky trap to watch for: Adding the two bars gives their combined total, not how many more one bar shows than the other. Can you show me that first move again in your own words? Brilliant. No rush; we are practising a method you can reuse, not trying to win a speed contest.

What this exercise is doing

Bar Reader

Tap the Train bar. Then read its top off the scale: how many children does it stand for?

This engine’s own main skill is Reading values off a bar chart. It practises compare bar-chart values alongside it.

The Train bar stops level with 30 on the scale. The lines on this chart go up in 5s, and only every other line carries a number, so the bare lines in between are the ones you have to count through. The top of the bar sits exactly on a line, so you can read it straight off. Keeping your finger level as you cross to the scale is what stops a reading landing one line out.

Step 1. Find it. Tap the bar the question names.
Step 2. Read it. Now read the scale and choose how many children that is.

What to say if they get stuck

Find the bar, row or slice the question names before you read anything. Getting the label right matters as much as the reading.
The scale does not always count up in single steps. Work out what a single line is worth before you read anything off it.
Keep your finger level as you slide from the board across to the scale. Drifting up or down by a line is the commonest slip there is.

Open Bar Reader on its own page to share it

Where compare bar-chart values sits in the 11+

The 11+ does not test these skills in isolation, and practising one in the wrong order wastes the practice. These are the skills the curriculum map connects this one to.

Secure this first: Read a bar-chart value
A comparison requires accurate scale reading.

How compare bar-chart values differs from the skills beside it

The same exercise practises one other skill, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: compare two category values on a bar chart, and it stops where one comparison or difference only.

Read a bar-chart value
Read one category value using the bar-chart scale. Excludes comparing several bars.

Related maths skills

Calculate an arithmetic meanFind the mean of a short supplied data set.
Compare line-graph changeCompare one change or gap between plotted values.
Compare table valuesCompare two values read from a table.
Decode a pictogram keyUse a pictogram key to determine one represented quantity.
Interpret a pie-chart sectorExpress one pie-chart sector as a fraction, percentage, or count.
Read a line-graph valueRead one plotted value at a named position.
Read a table cellFind one value at a named row and column.

All maths 11+ skills

Questions parents ask about compare bar-chart values

Answered from what the skill map records about this skill, not from a template. Every answer here is on the page, and the same questions are the page's FAQ structured data.

: Compare two category values on a bar chart. It is one of 55 named maths skills in the 11+, in the data strand, and this page carries 1 interactive exercise that practises it.
: The skill map puts read a bar-chart value first. A comparison requires accurate scale reading. If compare bar-chart values keeps going wrong, that is the thing to check before doing more of this one.
: Adding the two bars gives their combined total, not how many more one bar shows than the other. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.
: Point at the next move rather than explaining the whole rule. Read the Caldale bar and the Ashford bar off the scale first, then take the smaller number away from the larger one.
: The skill map draws the line here: One comparison or difference only. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.
: The data strand holds 9 skills that are tested together, and the pages next to compare bar-chart values are compare line-graph change, compare table values and decode a pictogram key. Each has its own exercise and its own link, and none of them needs an account.
: Use Bar Reader, embedded on this page. It is the exercise the skill map attaches to compare bar-chart values, it runs in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. It also has its own link, so you can send it to a child without sending them anywhere else first.

Compare bar-chart values rests on something else being secure first

This skill depends on read a bar-chart value. A free diagnostic checks those alongside every other maths skill, so you find out whether the problem is here or underneath it.

Start the free 11+ diagnostic