lessonfieldWhat they’re learning
Your child is learning to add and subtract whole numbers within 1,000 using place-value strategies and standard written methods. The goal is not only getting an answer, but understanding regrouping.
Explain it to my child
When there are more than 9 ones, we can trade 10 ones for 1 ten. Subtraction works the other way: if we need more ones, we can trade 1 ten for 10 ones.
Try it together
Use base-ten blocks, bundled straws, LEGO groups, or drawings of hundreds/tens/ones. Model 246 + 178, physically trading 10 ones for a ten and 10 tens for a hundred.
Practice
- 246 + 178 = ?
- 603 - 247 = ?
- 375 + 209 = ?
- 800 - 365 = ?
- Estimate 491 + 206 before calculating.
Check understanding
- Can your child tell when regrouping is needed?
- Can they use an estimate to notice an unreasonable exact answer?
Parent answer guide
- 424
6 + 8 makes 14 ones, so regroup. - 356
Borrow/regroup across the zero carefully. - 584
- 435
- About 700
491 is about 500 and 206 is about 200.
Ontario curriculum connection
Grade 3 · Mathematics
Number · Operations
Curriculum expectation: Specific expectation omitted because Lessonfield has not yet verified an expectation-level mapping for this guide.