What does a child have to do to add whole numbers or decimals in the 11+?

Calculate one addition with aligned place values. It is one of 55 named maths skills in the 11+, in the number strand, and this page carries 2 interactive exercises that practise it.

What is the trap in an 11+ add whole numbers or decimals question?

Line the decimal points up under each other, not the last digits. 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 add whole numbers or decimals in the 11+?

The skill map draws the line here: Operation is supplied. 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 add whole numbers or decimals?

The skill map connects it to solve a multi-step problem. A multi-step context may compose an addition step. That skill has its own page here.

How can my child practise add whole numbers or decimals for free?

Use Build the Wall and Bar Model Builder, embedded on this page. They are the exercises the skill map attaches to add whole numbers or decimals, they run in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. Each also has its own link, so you can send one to a child without sending them anywhere else first.

Maths · Number

Add whole numbers or decimals

Calculate one addition with aligned place values.

Practise it now

Every brick is the two bricks below it added together. Tap a gap and fill in all three.

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.

Adding to a value read off the line

Point B is marked on the number line. What is the total of the value at B and 4.5?

Each small step on this line is worth 0.1, and every labelled tick is ten steps on.

6.2
10.7
7.2
6.3

Answer: 6.2

How you get there

B sits at 1.7, so the sum is $1.7 + 4.5 = 6.2$ . Line the decimal points up under each other, not the last digits, because a digit only ever adds to a digit in the same place-value column.

Why the other answers tempt

Line the decimal points up under each other, not the last digits.

If they are stuck, say this

Work out what B is worth first by counting the small steps on from the labelled tick before it, then add 4.5 to it.

Now do it live in Build the Wall

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 Add whole numbers or decimals together. Take a look at the picture. Here is what matters: Number line from 0 to 3 in steps of 0.1 with major steps of 1. Here comes the question: Point B is marked on the number line. What is the total of the value at B and 4.5? Before we race ahead, let us choose one good first step. Here is a helpful clue: Work out what B is worth first by counting the small steps on from the labelled tick before it, then add 4.5 to it. Nice work. Now let us follow the thinking: Line the decimal points up under each other, not the last digits, because a digit only ever adds to a digit in the same place-value column. So our answer is: 6.2. There is one sneaky trap to watch for: Line the decimal points up under each other, not the last digits. 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.

How each of these 2 exercises teaches it

Build the Wall

Every brick is the two bricks below it added together. Tap a gap and fill in all three.

A number pyramid is just addition stacked up, but the order matters. Each brick needs BOTH bricks underneath it before you can work it out, so you always build from the bottom up. Here the bottom row 3, 5, 2, 6 gives 8, 7, 8 on the next row, then 15 and 15, and finally 30 on top. When a gap looks impossible, it is almost always because a brick below it is still missing. Fill that one first and the rest falls out.

What to say if they get stuck

Start at the bottom. A gap can only be filled once you can see both bricks holding it up.
The gap on the third row sits directly on 5 and 2 from the bottom row.
With the third row finished you have 8, 7, 8. That gives $8 + 7$ and $7 + 8$ on the next row, and the capstone is those two added together.

Open Build the Wall on its own page to share it

Bar Model Builder

Drag the number bricks into the bar model, then read off the answer.

This engine’s own main skill is Bar Models: Missing Part. It practises add whole numbers or decimals alongside it.

The whole is fixed at 142. The parts you already know fill 97 of it, so the empty piece must be $142 - 97 = 45$ .

What to say if they get stuck

Drag every brick into the model first - the picture does the thinking.
The parts you know sit inside the whole. The gap that is left over is what you are looking for.
The ? brace marks the empty piece of the whole bar. Read the numbers on the bars underneath it.

Open Bar Model Builder on its own page to share it

Where add whole numbers or decimals 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.

This is one piece of: Solve a multi-step problem
A multi-step context may compose an addition step.

How add whole numbers or decimals differs from the skills beside it

The same exercise practises several skills, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: calculate one addition with aligned place values, and it stops where operation is supplied.

Solve a one-step number problem
Choose and perform one operation in a short context. Exactly one operation is required.
Subtract whole numbers or decimals
Calculate one subtraction with aligned place values. Operation is supplied.

Related maths skills

Calculate a whole-number operationCalculate one stated addition, subtraction, multiplication, or division.
Compare and order numbersOrder or compare a bounded set of integers or decimals.
Continue a number sequenceInfer and apply one arithmetic sequence rule.
Divide whole numbers or decimalsCalculate one division and interpret any remainder as stated.
Evaluate a mixed expressionApply operation order to a supplied numerical expression.
Find a sequence termUse a stated or inferred linear rule to find a named term.
Multiply whole numbers or decimalsCalculate one multiplication using place-value reasoning or a written method.
Read place valueState the value of one digit in an integer or decimal.
Round to a stated placeRound one integer or decimal to the stated place value.
Scale by a power of tenMultiply or divide a number by 10, 100, or 1000 using place value.

All maths 11+ skills

Questions parents ask about add whole numbers or decimals

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.

: Calculate one addition with aligned place values. It is one of 55 named maths skills in the 11+, in the number strand, and this page carries 2 interactive exercises that practise it.
: Line the decimal points up under each other, not the last digits. 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. Work out what B is worth first by counting the small steps on from the labelled tick before it, then add 4.5 to it.
: The skill map draws the line here: Operation is supplied. 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 skill map connects it to solve a multi-step problem. A multi-step context may compose an addition step. That skill has its own page here.
: Use Build the Wall and Bar Model Builder, embedded on this page. They are the exercises the skill map attaches to add whole numbers or decimals, they run in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. Each also has its own link, so you can send one to a child without sending them anywhere else first.

Knowing which maths topic to practise is most of the work

A free diagnostic covers arithmetic, fractions, geometry, measure and data handling, and comes back with the topics to spend the next few weeks on.

Start the free 11+ diagnostic