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Maths · Number

Solve a one-step number problem

Choose and perform one operation in a short context.

Watch the worked example

One Story, One Operation

This video shows how to choose the operation needed to solve a short word problem and calculate the answer. Watch an 11+ maths question solved step by step.

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Quick quiz: Solve a one-step number problem

10 questions, with feedback after each one. No sign-up needed.

Read the questions in this quiz
  1. Question 1

    How many Morning passengers do Ashford and Eastwick have altogether?

    Bridgend
    Morning passengers
    506
    Evening passengers
    588
    Garndale
    Morning passengers
    364
    Evening passengers
    797
    Eastwick
    Morning passengers
    386
    Evening passengers
    411
    Denholm
    Morning passengers
    145
    Evening passengers
    347
    Caldale
    Morning passengers
    228
    Evening passengers
    157
    Ashford
    Morning passengers
    412
    Evening passengers
    91
    • A.26
    • B.798
    • C.412
    • D.2041
  2. Question 2

    How many April pots do Fuchsias and Roses have altogether?

    Roses
    March pots
    569
    April pots
    527
    Orchids
    March pots
    462
    April pots
    600
    Fuchsias
    March pots
    63
    April pots
    746
    Cacti
    March pots
    288
    April pots
    432
    Lavender
    March pots
    610
    April pots
    536
    Ferns
    March pots
    444
    April pots
    647
    • A.219
    • B.3488
    • C.746
    • D.1273
  3. Question 3

    How many Evening passengers do Ashford and Eastwick have altogether?

    Caldale
    Morning passengers
    753
    Evening passengers
    430
    Garndale
    Morning passengers
    182
    Evening passengers
    750
    Eastwick
    Morning passengers
    386
    Evening passengers
    44
    Bridgend
    Morning passengers
    247
    Evening passengers
    357
    Denholm
    Morning passengers
    480
    Evening passengers
    683
    Ashford
    Morning passengers
    299
    Evening passengers
    356
    • A.400
    • B.2620
    • C.356
    • D.312
  4. Question 4

    How many Track points do Blue and Yellow have altogether?

    Red
    Track points
    285
    Field points
    537
    Yellow
    Track points
    444
    Field points
    443
    Green
    Track points
    665
    Field points
    126
    Purple
    Track points
    410
    Field points
    478
    Blue
    Track points
    342
    Field points
    478
    • A.444
    • B.2146
    • C.786
    • D.102
  5. Question 5

    How many July bookings do Paddock and Woodland have altogether?

    Hilltop
    June bookings
    793
    July bookings
    608
    Orchard
    June bookings
    670
    July bookings
    691
    Copse
    June bookings
    232
    July bookings
    89
    Meadow
    June bookings
    689
    July bookings
    675
    Woodland
    June bookings
    694
    July bookings
    66
    Paddock
    June bookings
    545
    July bookings
    523
    • A.523
    • B.457
    • C.589
    • D.2652
  6. Question 6

    How many Morning sightings do Otters and Lemurs have altogether?

    Meerkats
    Morning sightings
    367
    Afternoon sightings
    102
    Bison
    Morning sightings
    774
    Afternoon sightings
    370
    Lemurs
    Morning sightings
    740
    Afternoon sightings
    678
    Otters
    Morning sightings
    715
    Afternoon sightings
    87
    Wolves
    Morning sightings
    287
    Afternoon sightings
    737
    Tapirs
    Morning sightings
    706
    Afternoon sightings
    74
    • A.3589
    • B.25
    • C.1455
    • D.740
  7. Question 7

    How many Year 5 entries do Rockets and Crystals have altogether?

    Pulleys
    Year 5 entries
    242
    Year 6 entries
    490
    Volcanoes
    Year 5 entries
    641
    Year 6 entries
    772
    Magnets
    Year 5 entries
    285
    Year 6 entries
    655
    Rockets
    Year 5 entries
    212
    Year 6 entries
    663
    Circuits
    Year 5 entries
    691
    Year 6 entries
    518
    Crystals
    Year 5 entries
    473
    Year 6 entries
    136
    • A.685
    • B.473
    • C.261
    • D.2544
  8. Question 8

    How many North plot trees do Oak and Beech have altogether?

    Birch
    North plot trees
    381
    South plot trees
    613
    Rowan
    North plot trees
    195
    South plot trees
    277
    Alder
    North plot trees
    787
    South plot trees
    265
    Beech
    North plot trees
    53
    South plot trees
    145
    Oak
    North plot trees
    52
    South plot trees
    428
    Hazel
    North plot trees
    748
    South plot trees
    365
    • A.2216
    • B.105
    • C.53
    • D.1
  9. Question 9

    How many Year 6 members do Choir and Judo have altogether?

    Coding
    Year 5 members
    330
    Year 6 members
    606
    Chess
    Year 5 members
    696
    Year 6 members
    200
    Drama
    Year 5 members
    513
    Year 6 members
    695
    Art
    Year 5 members
    483
    Year 6 members
    75
    Judo
    Year 5 members
    427
    Year 6 members
    207
    Choir
    Year 5 members
    621
    Year 6 members
    212
    • A.1995
    • B.5
    • C.419
    • D.212
  10. Question 10

    How many Evening passengers do Caldale and Garndale have altogether?

    Garndale
    Morning passengers
    528
    Evening passengers
    166
    Denholm
    Morning passengers
    110
    Evening passengers
    672
    Bridgend
    Morning passengers
    102
    Evening passengers
    329
    Caldale
    Morning passengers
    203
    Evening passengers
    181
    Ashford
    Morning passengers
    163
    Evening passengers
    670
    Eastwick
    Morning passengers
    355
    Evening passengers
    307
    • A.181
    • B.15
    • C.347
    • D.2325

Practise it now

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

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.

Choosing the operation from the words

How many July counts do Tadpoles and Beetles have altogether?

Creatures found at the nature reserve pond.

Beetles
April counts
53
July counts
55
Tadpoles
April counts
62
July counts
50
Snails
April counts
40
July counts
41
Newts
April counts
19
July counts
46

Data table with columns Creature, April counts, July counts. Rows: Creature Beetles, April counts 53, July counts 55; Creature Tadpoles, April counts 62, July counts 50; Creature Snails, April counts 40, July counts 41; Creature Newts, April counts 19, July counts 46.

Table columns: Creature, April counts, July counts. Rows: Beetles, 53, 55; Tadpoles, 62, 50; Snails, 40, 41; Newts, 19, 46.

  1. 55
  2. 192
  3. 105
  4. 5

Answer: 105

How you get there

"Altogether" asks for the two figures combined, so Tadpoles's 50 and Beetles's 55 are added, which gives 105 - the other rows are not part of the question.

Why the other answers tempt

Only the two rows named are involved, not the whole column.

If they are stuck, say this

Decide what "altogether" is asking you to do with the two figures before you touch the numbers.

Now do it live in Bar Model Builder

How each of these 4 exercises teaches it

Bar Model Builder

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

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

  1. Drag every brick into the model first - the picture does the thinking.
  2. The parts you know sit inside the whole. The gap that is left over is what you are looking for.
  3. 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

Balance Scale

Get ONE mystery bag alone on a pan - keeping the scale level - and you have found x.

This engine’s own main skill is Solving Equations. It practises solve a one-step number problem alongside it, and covers most of it rather than all.

A balanced scale is an equals sign made of metal. 2x + 3=11 means the two pans genuinely weigh the same. Remove 3 from both pans and it is still level: 2x = 8. Halve both pans and it is still level: x = 4. Every step of algebra is just something you did to both sides at once.

What to say if they get stuck

  1. Take a weight off one pan and watch what happens. The beam is telling you something.
  2. Whatever you take from one side, take the SAME from the other. Then it stays level.
  3. Once only bags are left on one side, split BOTH sides into that many equal groups.

Open Balance Scale on its own page to share it

Clock & Coins

The football match starts 1h 20m after 08:05. Wind the clock forward to find out when.

This engine’s own main skill is Time & Money. It practises solve a one-step number problem alongside it, and covers most of it rather than all.

Winding forward 1h 20m from 08:05 lands on 09:25 - the hour hand moves too, one twelfth as fast as the minute hand, which is why it sits between the numbers. Then 30p takes at least 3 coins from this tray: there is no 10p in it, so you have to build the amount from what is actually there.

  1. Step 1. Wind the clock. Wind the minute hand forward 1h 20m from 08:05.
  2. Step 2. Count the coins. A programme costs 30p. Drag coins into the purse to pay it exactly.

What to say if they get stuck

  1. Grab the long minute hand and wind it forwards. Watch the little hour hand creep round with it.
  2. One whole lap of the minute hand is one hour. You need 1h 20m.
  3. For the coins, start with the biggest coin that fits inside 30p and keep going.

Open Clock & Coins on its own page to share it

Step Builder

Build the answer one step at a time. Choose an operation, then choose the two numbers it works on.

This engine’s own main skill is Solving a problem in more than one step. It practises solve a one-step number problem alongside it.

Step 1 works out the pens that arrived: 60. Step 2 works out the pens left once the broken ones go: 56. Step 3 works out the pens one class gets: 7. So the answer is 7 pens. Doing the steps the other way round does not work, because the second step needs the first one's answer before it can start.

What to say if they get stuck

  1. You cannot get there in one go. What can you work out first, from two numbers the story already gives you?
  2. Once a step is done, its answer sits on the bench and can be used by the next step.
  3. This problem takes 3 steps. The last one ends with pens.

Open Step Builder on its own page to share it

How solve a one-step number problem 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: choose and perform one operation in a short context, and it stops where exactly one operation is required.

Related maths skills

All maths 11+ skills

Questions parents ask about solve a one-step number problem

What this skill involves, common mistakes and ways to practise it at home.

Choose and perform one operation in a short context. It is one of 55 named maths skills in the 11+, in the number strand, and this page carries 4 interactive exercises that practise it.

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.