Unit 2: Addition, Subtraction & Regrouping

Q1. 3,548 + 2,976 = ?

6524 6424 6514 6624

Solution: 3,548 + 2,976 = 6,524. Add ones, tens, hundreds, thousands, carrying as needed.

Q2. 7,203 u2212 4,586 = ?

2,717 2617 2527 2627

Solution: 7,203 u2212 4,586 = 2,617. Borrowing is needed in several columns.

Q3. 900 u2212 345 = ?

655 545 555 565

Solution: 900 u2212 345 = 555, borrowing across the zeros.

Q4. 5,000 u2212 2,678 = ?

2,332 2422 3322 2322

Solution: 5,000 u2212 2,678 = 2,322, borrowing across all three zeros.

Q5. 481 + 3,927 = ?

4,408 4308 4418 4398

Solution: 481 + 3,927 = 4,408.

Q6. Which addition checks that 6,004 u2212 2,758 = 3,246 is correct?

6004 +3246 3246+2758 2758-3246 3246-2758

Solution: Adding the answer back to what you subtracted should give the original number: 3,246 + 2,758 = 6,004.

Q7. 2,000 u2212 137 = ?

1,763 1873 1863 1963

Solution: 2,000 u2212 137 = 1,863.

Q8. 8,469 + 956 = ?

9,415 9325 9525 9425

Solution: 8,469 + 956 = 9,425.

Q9. 6,300 u2212 2,845 = ?

3,455 3555 3445 3465

Solution: 6,300 u2212 2,845 = 3,455.

Q10. Which problem requires borrowing across a zero to solve?

540 u2212120 800-235 650-410 999-111

Solution: In 800 u2212 235, both the tens and hundreds are zero in the ones/tens spot, so you must borrow from further left.

Q11. 372 + 658 + 41 = ?

1061 1171 1071 981

Solution: 372 + 658 = 1,030, then 1,030 + 41 = 1,071.

Q12. 4,001 u2212 1,999 = ?

2,102 1998 2012 2002

Solution: 4,001 u2212 1,999 = 2,002n

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