Definition:

Three-digit addition involves combining two or more numbers, each with three digits. This process is done by adding the values in the ones, tens, and hundreds of places, starting from the right (one's place) and moving to the left. If the sum in any place value exceeds 9, a carry is added to the next higher place value.

Example 1:

Add 345 and 7.

Solution:

• Write the numbers in column form: 345 + 7
• Add the ones place:5+7=12 (write 2, carry over 1 to the tens place)
• Add the tens place:4+1=5
• Add the hundreds place:3+0=3

Final solution: 345+7=352

Example 2:

Add 208 and 9.

Solution:

• Write the numbers in column form: 208 + 9
• Add the ones place:8+9=17 (write 7, carry over 1 to the tens place.)
• Add the tens place:0+1=1
• Add the hundreds place:2+0=2

Final solution: 208+9=217

Example 3:

Add 603 and 8.

Solution:

• Write the numbers in column form: 603 + 8
• Add the ones place:3+8=11 (write 1, carry over 1 to the tens place)
• Add the tens place:0+1=1
• Add the hundreds place:6+0=6

Final solution: 603+8=611

Why it matters:

Adding numbers is a fundamental math skill that helps solve everyday problems, from calculating expenses to measuring quantities. It builds a strong foundation for advanced arithmetic concepts like multiplication and division. Mastering addition improves problem-solving, logical thinking, and mental math abilities.

By practicing adding numbers, you can solve real-world problems quickly!

Let’s practice and evaluate your work together by adding numbers.