Concept 9 of 9
Word Problems: Ignore the Extra Information
Today's big idea
Read the final question first, then keep only the numbers it actually needs.
Some numbers are printed only to be left out, so check each against the question.
How it works
👀 What's going on?
Not every number in a word problem is there to be used. Some are put in to see whether you are reading or just grabbing.
💡 Here's the trick
Look at the problem above. The question at the end tells you which numbers count, so read that first. Anything the question does not need can be crossed out before you start.
🪄 How to do it
- 1.Read the last line of the problem above and name what it asks for.
- 2.List only the numbers that help answer that line.
- 3.Solve with those numbers, using BODMAS if there are several steps.
✍️ Try it
A bakery fills 24 trays with 12 buns each and the oven cost ₹9,000. How many buns is that? Then: Rohan has 60 marbles, gives 14 to Sia and 9 to Ved, and his bag cost ₹35. How many marbles are left?
The oven price is extra, so 24 × 12 = 288 buns. The bag price is extra too, so 60 − 14 − 9 = 37 marbles.
⚠️ Watch out
You might be thinking every number printed in a problem must be used somewhere. Many problems carry a spare on purpose. Check each number against the final question, and drop the ones it never mentions.
🌟 Why this matters
Adverts, bills and news bulletins are full of numbers you do not need. Picking out the ones that answer your question is a life skill.
Exam tip: Underline the final question first, then read the problem again with it in mind.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“Henry read 27 books. Each book had 9,047 words. He sold 5 books for $196.95 each. How many WORDS did Henry read?”
- 1
Read the question first
It asks about WORDS READ, not money. 🔍
- 2
Spot the extra info
“Sold 5 books for $196.95 each” → EXTRA, ignore.
- 3
Use the useful numbers
27 × 9,047
- 4
Multiply ✓
27 × 9,047 = 244,269 words
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Read the QUESTION first. Then tap the number the question does NOT need.
STORY · ROUND 1 OF 3
📚 A library has 640 books. Maya borrowed 3 books on Monday and 4 books on Friday.
How many books did Maya borrow in all?
Tap the EXTRA number:
Quick check
✅ VERIFICATION
Teddy bought 14 pizzas and each pizza had 8 slices. He ate one-quarter of all the slices. How many slices are LEFT?
⚡ Finish the activity above first to answer.
Keep going!