Grade 1 Operations & Algebraic Thinking Practice — Medium

Question 1 of 48Score 0/0Medium

Question 1 of 48: There are 15 fish in a tank. 6 swim away. How many fish remain?

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Answer key for parents & teachers (48 questions)
  1. There are 15 fish in a tank. 6 swim away. How many fish remain? — 9. 15 − 6 = 9 fish.
  2. Lily had 11 stickers. She gave some away and has 6 left. How many did she give away? — 5. 11 − 6 = 5 stickers were given away.
  3. A box had 14 crayons. 8 were broken. How many were NOT broken? — 6. 14 − 8 = 6 unbroken crayons.
  4. Two groups of ducks: 9 in the pond and 4 on the bank. How many ducks altogether? — 13. 9 + 4 = 13 ducks in all.
  5. A garden has 8 red flowers and 7 yellow flowers. How many flowers in all? — 15. 8 + 7 = 15 flowers.
  6. A shelf had 16 books. Some were returned to the library, leaving 9. How many were returned? — 7. 16 − 9 = 7 books returned.
  7. Sam counted 5 big dogs and some small dogs. There are 13 dogs in all. How many small dogs? — 8. 13 − 5 = 8 small dogs.
  8. Amy picked 6 apples. Beth picked 4 fewer than Amy. How many did Beth pick? — 2. "Fewer" means subtract: 6 − 4 = 2 apples.
  9. Jake has 9 kites. If he gives away kites until he has 5, how many did he give away? — 4. 9 − 5 = 4 kites given away.
  10. Mia counted 18 buttons in a jar. She removed some until there were 9. How many did she remove? — 9. 18 − 9 = 9 buttons removed.
  11. (2 + 3) + 4 = 2 + (3 + 4). This shows which property? — Associative. The Associative Property says grouping does not change the sum.
  12. Which set of additions all equal the same sum? — 5+4 and 4+5. 5+4 = 9 and 4+5 = 9 — that is the commutative property.
  13. Which grouping of 2 + 5 + 3 is easiest to compute? — Both give 10. Both groupings give 10! The associative property guarantees this.
  14. What is the easiest way to add 1 + 8? — Start at 8 and count up 1. Start with the bigger number (8) and count up 1 — much faster!
  15. (3 + 7) + 5 = ? — 15. (3 + 7) + 5 = 10 + 5 = 15.
  16. 3 + (7 + 5) = ? — 15. 3 + (7 + 5) = 3 + 12 = 15. Same answer — associative property!
  17. A boy has 4 red marbles and 7 blue marbles. A girl has 7 red and 4 blue. Who has more marbles? — They have the same. 4 + 7 = 11 and 7 + 4 = 11. Commutative property — same total!
  18. What is 5 + (5 + 2)? — 12. 5 + (5 + 2) = 5 + 7 = 12.
  19. Which choice shows the associative property? — (3 + 4) + 2 = 3 + (4 + 2). Regrouping addends without changing the sum — that is the associative property.
  20. What is 4 + 6 + 3? — 13. 4 + 6 = 10, then 10 + 3 = 13.
  21. Add in the easiest order: 7 + 3 + 8 — 18. 7 + 3 = 10 (easy pair!), then 10 + 8 = 18.
  22. True or False: 7 + 3 = 5 + 5 — True. 7 + 3 = 10 and 5 + 5 = 10. Both sides equal 10 — TRUE!
  23. Which makes this equation true? 6 + __ = 3 + 7 — 4. 3 + 7 = 10. So 6 + __ = 10 means __ = 4.
  24. What value of ? makes 5 + ? = 4 + 4? — 3. 4 + 4 = 8, so 5 + ? = 8, meaning ? = 3.
  25. Is 12 = 7 + 6? — No, 7+6=13. 7 + 6 = 13, not 12. So 12 ≠ 13. The equation is FALSE.
  26. Which pair of expressions are equal? — 6+2 and 7+1. 6+2=8 and 7+1=8. Both equal 8!
  27. Which equation has an equal sign in an unusual but still correct place? — 8 = 3 + 5. 8 = 3 + 5 is correct — the sum on the right (8) matches the left side!
  28. Fill in: 5 + 5 = ___ + 3 — 7. 5 + 5 = 10. So ___ + 3 = 10 means ___ = 7.
  29. Which equation shows 10 made two different ways? — 10 = 5 + 5 and 10 = 6 + 4. 5+5=10 and 6+4=10. Both expressions equal 10!
  30. What strategy helps find missing numbers? — Use related subtraction fact. If a + __ = c, then __ = c − a. Subtraction is the key!
  31. 13 + __ = 20 — 7. 20 − 13 = 7. Check: 13 + 7 = 20 ✓
  32. A bag has some apples. You put in 4 more and now have 11. How many were there at first? — 7. 11 − 4 = 7 apples were in the bag at first.
  33. __ + 7 = 15 — 8. 15 − 7 = 8. Check: 8 + 7 = 15 ✓
  34. 5 + __ = 14 — 9. 14 − 5 = 9. Check: 5 + 9 = 14 ✓
  35. What is the missing number? __ = 16 − 8 — 8. 16 − 8 = 8. The missing number is 8.
  36. Which equation has 5 as the missing number? — 9 + __ = 14. 9 + 5 = 14. All the others have a different missing number.
  37. If 10 − __ = 4, what is the missing number? — 6. 10 − 6 = 4. Check: 4 + 6 = 10 ✓
  38. 12 + __ = 20 — 8. 20 − 12 = 8. Check: 12 + 8 = 20 ✓
  39. Count on strategy: 8 + __ = 12 — count up from 8 to 12. How many steps? — 4. 9, 10, 11, 12 — that is 4 steps up from 8. So the missing number is 4.
  40. A jar has some jellybeans. After adding 6, there are 14. How many were there before? — 8. 14 − 6 = 8 jellybeans were in the jar before.
  41. Write all 4 facts for the family 2, 6, 8. Which is NOT in the family? — 6 − 2 = 8. 6 − 2 = 4, not 8. That fact does not belong to this family!
  42. What is the missing fact? 5 + 9 = 14; 9 + 5 = 14; 14 − 5 = 9; 14 − __ = 5 — 9. 14 − 9 = 5. That completes all four facts in the family!
  43. Tom knows that 8 − 3 = 5. Which fact does he also know for FREE? — 5 + 3 = 8. They are in the same fact family! 5 + 3 = 8 (and 3 + 5 = 8).
  44. In which fact family does 16 appear as the LARGEST number? — 7, 9, 16. 7 + 9 = 16. Only family 7, 9, 16 is correct.
  45. How does knowing a fact family help with subtraction? — You can turn subtraction into addition. If you know 4 + 9 = 13, you automatically know 13 − 9 = 4 and 13 − 4 = 9!
  46. If 15 − 9 = 6, which addition fact is in the same family? — 9 + 6 = 15. 9 + 6 = 15 belongs to the same family as 15 − 9 = 6.
  47. The largest number in a fact family is always the __? — Sum of the two other numbers. The largest number is the SUM of the two smaller numbers. 4 + 7 = 11; 11 is the largest.
  48. Which fact belongs to the family 10, 4, 6? — 10 − 6 = 4. 10 − 6 = 4. The family has 6+4=10; 4+6=10; 10−6=4; 10−4=6.