30% off your first 3 months

Get the deal

Reading word problems without panic

by DuckyHelperNov 12, 20265 min read
Study skills

TL;DR:

  • Read twice. First for the story, then for the numbers.

  • Underline every quantity, define each variable with its unit, and estimate the answer before you calculate.

  • Translate the story into one equation, solve it, then check it against the story, not just the algebra.

A paragraph of text with four numbers hidden in it can make a student who is fine at algebra freeze. The algebra is not the hard part. The hard part is that nobody told you which numbers matter, which are decoration, and what the unknown is.

The fix is a routine that turns the paragraph into a small table of facts before you write a single equation. Panic comes from not knowing where to start, so give yourself a start that always works.

Why a routine beats a flash of insight

Strong problem solvers do not see the equation instantly. They do the same boring steps every time: find what is asked, list what is given, name the unknown, picture the situation. The boring steps are what make the insight possible.

A routine also keeps your head quiet. When the first step is "underline numbers" you have something to do with your hands even when the problem looks hard.

What you need

  • A pencil, and a copy of the problem you are allowed to mark up.

  • Scrap space for a quick sketch or a table.

  • The habit of writing units next to every number.

The routine

  1. Read once for the story: Do not calculate. Just ask: who or what is moving, changing or being compared? Sketch it if you can.

  2. Underline quantities and circle the question: Underline every number with its unit and circle the last sentence, the thing you must find. Cross out nothing yet.

  3. Define variables with units: Write "let t = hours after 10:00", not just "let t = time". The unit and the starting point are part of the definition.

  4. Estimate the answer: Make a rough guess in your head, even a crude one. It gives you a target to compare your result with later.

  5. Write one equation, solve, then check against the story: Say in words what the equation means before you solve it. Afterward, plug the answer back into the original sentences.

Worked example: a train that catches up

Here is the problem. A train leaves a station at 9:00 travelling at 60 km/h. A second train leaves the same station on the same track at 10:00 travelling at 90 km/h. At what time does the second train catch the first?

Quantities. 60 km/h, 9:00, 90 km/h, 10:00. Question. A clock time. Notice the answer must be a time, not a number of hours, so you will need to convert at the end.

Estimate. By 10:00 the first train is 60 km ahead (one hour at 60 km/h). The second train gains 90 − 60 = 30 km on it every hour. To close a 60 km gap at 30 km per hour takes about 2 hours, so the catch-up should be near 12:00.

Define. Let t = hours after 10:00. At time t the second train has gone 90t km. The first train has been travelling for t + 1 hours, so it has gone 60(t + 1) km.

  1. They meet when the distances are equal: 90t = 60(t + 1).

  2. Expand: 90t = 60t + 60.

  3. Subtract 60t: 30t = 60.

  4. Divide: t = 2.

So the catch-up happens 2 hours after 10:00, at 12:00. It matches the estimate.

Check against the story. The first train has travelled 3 hours (9:00 to 12:00) at 60 km/h, which is 3 × 60 = 180 km. The second has travelled 2 hours at 90 km/h, which is 2 × 90 = 180 km. Same place, same moment. The check uses the original wording, not your equation, so it would catch a wrong equation as well as wrong arithmetic.

What a wrong setup looks like

A common slip is to write 90t = 60t and forget the head start. That gives t = 0, which says the trains meet at the station at 10:00. Your estimate already told you that is nonsense, so the estimate step catches the mistake before you hand it in.

Words that signal operations

Some phrases point to a structure, but treat them as hints, not rules. Always test them against the story.

Phrase

Often means

Watch out for

catches up, meets

set two distances equal

different starting times or places

per, each, every

a rate: divide or multiply

units that do not match (minutes vs hours)

more than, less than

add or subtract

order: 5 less than x is x − 5

total, altogether

add the parts

parts that overlap

Mistakes to avoid

  • Grabbing the first two numbers and combining them without asking what they measure.

  • Mixing units, such as minutes with km/h, without converting.

  • Defining a variable vaguely, so you forget whether t starts at 9:00 or 10:00.

  • Stopping at the algebra answer. Always put it back in the story.

  • Giving a bare number when the question wants a time, a unit or a sentence.

Your plan for this week

Take three word problems from your homework. For each, do only the first four steps: underline, circle, define, estimate. Do not solve yet. Then solve them and see how often your estimate saved you. Do this for a week and the freeze fades, because you always know what to do first.

Frequently asked questions

What if I cannot make an estimate?

Try easier numbers. Imagine the second train goes 100 km/h and the first 50, and see what happens. The shape of the answer usually carries over.

Should I draw a picture every time?

When something moves, changes over time or has parts, yes. A quick line with labels is enough, and it often shows the head start or the overlap you would otherwise miss.

Get started

DuckyHelper can
do more

It sees your screen and works in any app you use. Try it for 10 minutes, no card.

Get it for Mac, Windows or Linux

Share

Questions and jobs

Do anything

Ask it a question or hand it a job, in any app.

Doing jobs for you is in early access on Mac. Asking works on Mac, Windows and Linux.