🧮 Addition Within 100 — Adding Two-Digit Numbers Without Regrouping
Explore the Coral Reef with Captain Coral!
Read the Story First!
🔤 Words to Know
Two-digit number — A number with two digits, like 34 or 67.
Sum — The answer when you add numbers together.
Captain Coral and Wanda were exploring the shallow lagoon when they found two groups of tropical fish. The first group had 23 clownfish hiding in the coral. The second group had 14 angelfish swimming nearby.
"How many fish altogether?" asked Wanda.
Captain Coral thought about it. He started with the ones column: "3 ones plus 4 ones equals 7 ones." Then the tens: "2 tens plus 1 ten equals 3 tens."
"So 23 + 14 = 37 fish!" said Captain Coral.
"When you add two-digit numbers, always start with the ones column first, then move to the tens," said Wanda. "Line them up carefully!"
Captain Coral tried another: "42 + 35. Ones: 2+5=7. Tens: 4+3=7. The sum is 77!"
"You are adding like a second-grader now!" said Wanda.
🧠 Answer the Questions
Read each question carefully. Pick the best answer!
What does it mean to add two-digit numbers?
Which column do you add first?
23 + 14 = ?
42 + 35 = ?
What is the sum?
51 + 28 = ?
How many fish were in the first group?
What is a two-digit number?
30 + 40 = ?
When adding, what column comes after ones?