Read twice, count once
A word problem is a question in disguise. Someone took counting, dressed it in a story about stickers or a trip, and your job is to undress the question again.
Most mistakes in word problems are not counting mistakes at all. They are reading mistakes: a wrongly understood question, a missed word, a number used only because it was there.
That is why today’s rule sounds like the one from carpenters. They say: measure twice, cut once. We say: read twice, count once.
The first reading is for the story — no pencil, just understand what is happening. The second reading is with a pencil — underline the numbers, find the question, decide what will be counted. Only then do you count. And the counting is usually the easier half.
Adam reads a problem with one eye, sees the numbers 24 and 8 in it, slaps 24 + 8 = 32 and goes. But the problem asked how many more Ema has than Tereza — the right thing was to subtract.
Sofie reads the same problem twice. On the second reading she underlines the numbers and circles the question: “How many more…?” Out loud she says: “They ask for the difference, not altogether.” She counts 24 − 8 = 16 and writes the answer in a full sentence.
Adam counted faster. Sofie counted the right thing. Guess which one maths values more.
The question is the boss of the whole problem — usually it is the last sentence with a question mark and the word how many. Find it and circle it first. Everything else in the problem either helps the boss answer, or is only there for the numbers.
Four steps to undress a problem
Step 1: read the whole problem without a pencil. Just the story: who, what, what happened. If after the first reading you had to tell the story to grandma, could you? If not, read again.
Step 2: second reading with a pencil. Underline every number. Circle the question. At each underlined number ask: does the boss-question need you, or are you only here for show? Problems sometimes put in an extra number on purpose.
Step 3: decide the operation. Words in the problem hint. Altogether, in total, more arrived, got another — they smell of addition. Left, gone, ate, how many more, how many fewer, difference — they smell of subtraction. But watch: they hint, they do not command. The word “more” in the question “how many more” means subtraction! So the sense of the story always decides, not one word.
Step 4: count and answer in a sentence. The result 16 is not an answer. The answer is: “Ema has 16 more stickers.” A sentence with units forces you to check that the result even makes sense in the story.
Example 1: a two-step problem
“Ema has 24 stickers. Tereza has 8 fewer. How many stickers do they have altogether?”
Second reading: numbers 24 and 8, boss-question: altogether. Watch — a trap: you cannot add 24 + 8 altogether, because 8 is not Tereza’s amount! The eight only says how many fewer Tereza has.
First step: how many does Tereza have? 24 − 8 = 16.
Second step: altogether. 24 + 16: tens 20 + 10 = 30, ones 4 + 6 = 10, in total 30 + 10 = 40.
Answer in a sentence: Altogether they have 40 stickers.
Example 2: a number for show
“In Year 4B there are 12 boys and 14 girls. The teacher has taught at the school for 8 years. Today 5 children are away. How many children sit in the class today?”
Second reading: numbers 12, 14, 8 and 5. Boss-question: how many children sit in the class today. I ask each number: 12 and 14 — those are children, I need you. 5 — children away, I need you. 8 — the teacher’s years? They have nothing to do with the number of children. For show. I cross it out.
Calculation: all children are 12 + 14 = 26. Today 5 are away, so 26 − 5 = 21.
Answer: 21 children sit in the class today. The eight stayed unused — and that is right.
The biggest trap of word problems: pick up every number from the text and join them somehow. Not every number belongs in the calculation — who to invite is decided by the question, not by the fact that a number is simply in the text.
Practice: now you do it 🎲
Now try it for real. You will see all the questions at once, like on paper. Start with ten. When it goes well, add more.
How many more? Read the question twice, then count.
On paper: undress three problems
For each problem the whole ritual: two readings, underline, circle the boss, decide, count, answer in a sentence.
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“Jonáš had 50 Kč. He bought a snack for 32 Kč. How much did he have left?” Run all four steps and answer in a sentence.
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“Filip collected 27 chestnuts, Sofie 15 more. How many chestnuts did Sofie collect?” Watch the word more — this time it really commands addition. Explain in one sentence why.
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“There were 18 children on the playground. Another 7 arrived and then 9 children went home. It is 26 degrees outside. How many children are on the playground?” Find the number for show, cross it out and finish the count.
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Make up your own word problem with one extra number and give it to someone at home to solve. Check if your trap-number catches them.
Now you 💪
- I read a problem twice: first the story, second with a pencil the numbers and the question.
- I can spot a number that does not belong in the calculation.
- I answer in a full sentence with units, not just a number.
Done when: You have three undressed problems with answers in sentences and one of your own problems with a trap that works.
What to take from this lesson
- A word problem is a question in disguise — undress it first.
- First reading for the story, second with a pencil for the numbers and the question.
- The question is the boss. It decides which numbers to invite into the calculation.
- Words hint the operation, but the sense of the story commands.
- The answer is a sentence with units, not a bare number.
© 2026 Ing. Martin Polak / AlgoRhino · Content usage terms