Cogito
Grade 2 Math · Chapter 5 · Lesson 8
Word Problems Within 1,000
Bigger numbers, same thinking.
10 problems · about 15 minutes · 2.OA.A.1, 2.NBT.B.7
What this lesson teaches
The child solves one- and two-step word problems with numbers to 1,000.
- Bigger numbers do not change the thinking.
- Estimate first, so a wrong answer stands out.
- Check at the end by adding back.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Adding Up to Four Numbers: 13 + 27 + 20 = ?
Answer 60
Why 40 + 20 = 60.
Review — Subtracting Across a Zero: 405 − 137 = ?
Answer 268
Why 405 − 137 = 268.
Warm Up
Straightforward practice. Get the method working first.
3 problems462 + 289 = ?
Answer 751
Why 462 + 289 = 751.
Why estimate before working it out?
Answer To catch a wildly wrong answer.
Why An estimate tells you roughly where the answer should land.
318 + 245 = ?
Answer 563
Why 8 and 5 makes a new ten.
Build It Up
The same ideas with more to keep track of.
1 problem604 − 271 = ?
Answer 333
Why Break a hundred.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problems250 more than 375 is?
Answer 625
Why 7 tens and 5 tens.
The Football Match: 345 adults and 268 children came to a match. How many people came?
Answer 613 people
Why 345 + 268 = 613.
The Book Drive: A target of 500 books has 236 collected. How many more are needed?
Answer 264 books
Why 500 − 236 = 264.
Two Steps: A shop had 420 items, got 175 more, then sold 260. How many now?
Answer 335 items
Why 595 − 260 = 335.