Grade 4
Grade 4 math: Add and subtract 4-digit numbers, including across zeros
By Tutorizer · 3 min read · The math examples come from our own lessons and are checked by our tools.
If your child is in Grade 4, the topic "Add and subtract 4-digit numbers, including across zeros" is one of the ideas where confidence is most often won or lost. Here is what it means in plain words, a worked example you can follow together, and a few simple ways to help at home.
What Grade 4 children learn
- Add 4-digit numbers, trading 10 of one place for 1 of the next place
- Subtract when there are zeros in the middle, by trading from the next place that has something to give
- Estimate by rounding first, and check a subtraction by adding
The key ideas
- The places are ones, tens, hundreds and thousands. 10 of one place make 1 of the next place.
- To add, start at the ones. If a place makes 10 or more, trade 10 of it for 1 of the next place.
- To subtract, you may need to trade. If the next place is 0, go further left to find something to trade, then pass it along.
- Check a subtraction by adding the answer to the number you took away. You should get back to the start.
- Estimate first by rounding to the nearest hundred, so you know about how big the answer should be.
Quick examples
- 3675 + 2859 = 6534
- 4002 − 1768 = 2234
- 5000 − 2346 = 2654
- Estimate 7814 − 3196: 7800 − 3200 = 4600, so the exact answer 4618 should be close to that
A worked example
Work out 7005 − 2468.
- We cannot take 8 ones from 5 ones, and the tens and hundreds are both 0. Go to the thousands.
- Trade 1 thousand for 10 hundreds, 1 hundred for 10 tens, and 1 ten for 10 ones. Now we have 6 thousands, 9 hundreds, 9 tens and 15 ones.
- Subtract each place: 15 − 8 = 7 ones, 9 − 6 = 3 tens, 9 − 4 = 5 hundreds, 6 − 2 = 4 thousands.
- Check: 4537 + 2468 = 7005.
Answer: 4537
How to help at home
- Ask your child to explain the first step of the worked example in their own words before you show them anything.
- Work through the "Try it yourself" question together, and talk about why the answer makes sense.
- Spend a few minutes a day on the free Tutorizer "Adding and subtracting" practice. Short and regular beats long and rare.
- If a step feels shaky, go back to the key ideas above and use objects, drawings or a number line.
Try it yourself
Work out 8040 − 3675.
Show the answer
Answer: 4365
- We cannot take 5 ones from 0 ones, so trade 1 ten for 10 ones: 4 tens becomes 3 tens, and we have 10 ones. 10 − 5 = 5 ones.
- We cannot take 7 tens from 3 tens, and the hundreds place is 0. Trade 1 thousand for 10 hundreds, then 1 hundred for 10 tens: 7 thousands, 9 hundreds and 13 tens.
- Subtract: 13 − 7 = 6 tens, 9 − 6 = 3 hundreds, 7 − 3 = 4 thousands.
- The answer is 4365. Check: 4365 + 3675 = 8040.
Want a challenge?
A hockey arena has 6003 seats. On Saturday 2487 seats are sold, and on Sunday 1956 more seats are sold. How many seats are still empty?
Show the answer
Answer: 1560
Next steps
Not sure where your child stands? Start with a free 15-question check-in. It takes about 15 minutes, has no pass or fail, and shows what is solid and what needs practice.
Start the free check-inPractice with the free math games, no card needed.
Play the free gamesWant live help? Take a look at Grade 4 Toughest Topics, taught live on Zoom in a small group.
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