🧮 Subtraction Within 100 — Subtracting Two-Digit Numbers Without Regrouping
Explore the Coral Reef with Scuba Bob!
Read the Story First!
🔤 Words to Know
Difference — The answer when you subtract one number from another.
Subtract — To take one number away from another.
There were 78 hermit crabs on the beach. 35 of them crawled back to the water.
"How many are left?" asked Finn.
Scuba Bob set up the problem: "78 - 35. Start with ones: 8 - 5 = 3. Then tens: 7 - 3 = 4."
"78 - 35 = 43 hermit crabs still on the beach!"
"No regrouping needed because each top digit was bigger than the bottom digit," said Finn.
Scuba Bob tried 96 - 42: "Ones: 6-2=4. Tens: 9-4=5. Answer: 54!"
"Always subtract ones first, then tens," said Finn. "And check your work by adding: 43 + 35 should equal 78."
Scuba Bob checked: "43 + 35 = 78. It works!"
🧠 Answer the Questions
Read each question carefully. Pick the best answer!
What was the math topic?
Who helped Scuba Bob learn?
What is difference?
34 + 25 = ?
67 - 23 = ?
What comes first when adding two-digit numbers?
45 + 38 = ?
90 - 56 = ?
What is subtract?
52 + 19 = ?