Add and Subtract Multi-Digit Numbers - 4th Grade Math

1. What is $12{,}000 - 3{,}999$?

   $8{,}001$. Borrow across three zeros to subtract $3{,}999$.

2. Identify the missing digit: $9\square{,}450 - 3{,}275 = 66{,}175$.

   $9$. $66{,}175 + 3{,}275 = 69{,}450$, so missing digit is 9.

3. What is $3{,}999 + 2{,}006$ using the standard algorithm?

   $6{,}005$. Carrying from ones and tens columns gives the result.

4. What is $72{,}040 + 19{,}960$ using the standard algorithm?

   $92{,}000$. Ones cancel out; tens carry makes exactly 92,000.

5. Find and correct the error: $9{,}002 - 4{,}738 = 4{,}364$.

   Correct difference: $9{,}002 - 4{,}738 = 4{,}264$. Error in hundreds: after borrowing, $9-7=2$.

6. What is $58{,}746 + 23{,}159$?

   $81{,}905$. $6+9=15$ (write $5$, carry $1$), continue left.

7. What is $6{,}000 - 2{,}999$ using the standard algorithm?

   $3{,}001$. Borrow from 6,000 to subtract 2,999.

8. Find the value of $x$: $x + 28{,}645 = 90{,}000$.

   $61{,}355$. Subtract: $90{,}000 - 28{,}645 = 61{,}355$.

9. What is $80,500 - 12,775$ using the standard algorithm?

   $67{,}725$. Borrow from tens of thousands to complete the subtraction.

10. Find the value of $y$: $75{,}000 - y = 18{,}492$.

    $56{,}508$. Subtract: $75{,}000 - 18{,}492 = 56{,}508$.

11. What is $6{,}048 + 9{,}952$?

    $16{,}000$. $8+2=10$ (carry $1$), sum equals exactly $16{,}000$.

12. What is $70{,}000 - 8{,}765$?

    $61{,}235$. Regroup from each place value sequentially.

13. What is $83{,}402 - 27{,}615$?

    $55{,}787$. Borrow from tens, hundreds, and thousands places.

14. What is $6{,}708 + 3{,}295$ using the standard algorithm?

    $10{,}003$. Sum each place value, carrying 1 when sum ≥ 10.

15. What is $9,000 - 4,627$ using the standard algorithm?

    $4{,}373$. Borrow from thousands to subtract 627 from 000.

16. What is $50{,}000 - 1$?

    $49{,}999$. Borrow $1$ from tens place: $10-1=9$.

17. What is $65{,}432 + 8{,}568$ using the standard algorithm?

    $74{,}000$. Add each column; carries make the sum exactly 74,000.

18. Which place value is directly to the left of the thousands place?

    The ten-thousands place. Each place is $10$ times the place to its right.

19. What is $39,999 + 1$ using the standard algorithm?

    $40{,}000$. Adding 1 to 9 in the ones place causes carrying through all places.

20. What is $800{,}000 - 456{,}789$ using the standard algorithm?

    $343{,}211$. Borrow across multiple zeros from 800,000.

21. What is $100,000 - 1$ using the standard algorithm?

    $99{,}999$. Subtracting 1 from 100,000 requires borrowing through all places.

22. What is the first step in the standard algorithm for subtracting multi-digit numbers?

    Subtract the ones place digits first. Begin right to identify when borrowing is needed.

23. What is $4,586 + 2,739$ using the standard algorithm?

    $7{,}325$. Add column by column from right to left, carrying when needed.

24. What does it mean to "regroup" when adding in the standard algorithm?

    Trade $10$ of one place value for $1$ of the next place. Exchange when a column sum exceeds $9$.

25. What is $3,001 + 6,999$ using the standard algorithm?

    $10{,}000$. Strategic numbers that sum to exactly 10,000.

26. Identify the missing digit: $58{,}7\square 4 + 12{,}356 = 71{,}140$.

    $4$. $71{,}140 - 12{,}356 = 58{,}784$, so missing digit is 4.

27. What is the first step in the standard algorithm for adding multi-digit numbers?

    Add the ones place digits first. Start from the rightmost column to handle regrouping properly.

28. Find and correct the error: $3{,}478 + 2{,}596 = 5{,}064$.

    Correct sum: $3{,}478 + 2{,}596 = 6{,}074$. Error in ones place: $8+6=14$, not $4$.

29. What is $40,000 - 19,999$ using the standard algorithm?

    $20{,}001$. Borrowing through zeros gives this exact result.

30. What is $8,004 + 1,996$ using the standard algorithm?

    $10{,}000$. Carrying creates a sum that rounds to exactly 10,000.

31. What is $60,060 - 40,040$ using the standard algorithm?

    $20{,}020$. Simple subtraction with no borrowing needed.

32. What is $90{,}005 + 9{,}997$ using the standard algorithm?

    $100{,}002$. Carry from ones to tens, tens to hundreds, etc.

33. What is $5,432 + 9,568$ using the standard algorithm?

    $15{,}000$. The sum creates exactly 15,000 through carrying.

34. What is $50,000 - 27,846$ using the standard algorithm?

    $22{,}154$. Borrow from each place value to subtract the larger digits.

35. What is $100{,}000 - 99{,}999$?

    $1$. Only the ones place differs by $1$.

36. What does it mean to "borrow" (regroup) in subtraction?

    Trade $1$ from a higher place for $10$ in the next lower place. Enables subtraction when top digit is smaller.

37. What is $100{,}000 - 1$ using the standard algorithm?

    $99{,}999$. Subtracting 1 from 100,000 requires borrowing from each place.

38. What is $12,345 + 6,789$ using the standard algorithm?

    $19{,}134$. Multiple carries occur when adding these two numbers.

39. What is $999{,}999 + 1$ using the standard algorithm?

    $1{,}000{,}000$. Adding 1 to all 9s creates a cascade of carries.

40. What is $63,708 - 29,415$ using the standard algorithm?

    $34{,}293$. Subtract column by column, borrowing from left when needed.

41. What is $70{,}000 - 6{,}725$ using the standard algorithm?

    $63{,}275$. Borrow from ten-thousands to subtract in each column.

42. What is $10,000 - 3,999$ using the standard algorithm?

    $6{,}001$. Borrowing cascades through zeros to complete subtraction.

43. What is $35{,}435 + 28{,}079$?

    $63{,}514$. $5+9=14$ (carry $1$), continue adding left.

44. What is the value of the digit $7$ in the number $57,203$?

    $7{,}000$. The digit 7 is in the thousands place, representing 7 thousands.

45. What is a quick way to check $63{,}514 - 28{,}079$ using addition?

    Check that $28{,}079 + 35{,}435 = 63{,}514$. Subtraction and addition are inverse operations.

46. What is $9{,}999 + 1$?

    $10{,}000$. $9+1=10$, requiring regrouping at each place.

47. What is $84{,}261 - 37{,}498$ using the standard algorithm?

    $46{,}763$. Borrow from left columns when top digit is smaller.

48. What is $407{,}586 + 92{,}414$ using the standard algorithm?

    $500{,}000$. Multiple carries create the round sum of half a million.

49. What is $40{,}500 - 19{,}875$ using the standard algorithm?

    $20{,}625$. Borrow from 40,500 to complete the subtraction.

50. What is $54,321 - 9,876$ using the standard algorithm?

    $44{,}445$. Standard subtraction with borrowing from multiple places.

51. What is $50{,}000 - 27{,}845$ using the standard algorithm?

    $22{,}155$. Borrow across zeros by treating 50,000 as 49,999 + 1.

52. What is $1{,}000{,}000 - 999{,}998$ using the standard algorithm?

    $2$. After borrowing through all places, difference is 2.

53. What is $48{,}376 + 27{,}519$ using the standard algorithm?

    $75{,}895$. Add column by column from right to left, carrying when needed.

54. What should you do first if two addends have different numbers of digits?

    Line up the digits by place value (align ones under ones). Proper alignment ensures correct place value addition.

55. What is $28,406 + 7,595$ using the standard algorithm?

    $36{,}001$. Carrying occurs in ones, tens, and hundreds places.

56. What is $7{,}305 + 2{,}680$?

    $9{,}985$. $5+0=5$, $0+8=8$, $3+6=9$, $7+2=9$.

57. What is $7,070 + 9,095$ using the standard algorithm?

    $16{,}165$. Add column by column with carries in multiple places.

58. What is $70,030 - 58,094$ using the standard algorithm?

    $11{,}936$. Multiple borrowing needed across zeros in the minuend.

59. What is $40{,}006 - 2{,}789$?

    $37{,}217$. Borrow across zeros: $10-9=1$, $9-8=1$, etc.

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