Add two multiples of ten
key notes :
🔢 What Are Multiples of 10?
- Numbers that end in 0.
- Examples: 10, 20, 30, 40, 50, …
➕ When We Add Multiples of 10
- We add only the tens place.
- The ones place stays 0.
Example:
- 20 + 30 = 50
- Add 2 tens + 3 tens = 5 tens → 50
🧠 Use Tens Blocks or Bundles
- 10 ones = 1 ten stick.
- Adding multiples of 10 is like adding ten sticks.
Example:
- 40 = 4 tens
- 30 = 3 tens
- 4 tens + 3 tens = 7 tens → 70
🎯 Skip Counting Helps
- Use skip count by 10s:
10, 20, 30, 40, 50, 60…
Example:
- Start at 30 → count up 40 more by tens:
30 → 40 → 50 → 60 → 70
🧩 No Carrying Needed
- Adding multiples of 10 is easy because
there is no regrouping/carrying.
Example:
60 + 20 = 80
🍎 Addition Facts to Remember
- 10 + 10 = 20
- 20 + 20 = 40
- 30 + 40 = 70
- 50 + 30 = 80
🎉 Real-Life Examples
- Adding pencils in packs of 10
- Counting tens of candies
- Adding tens of pages in a book
Example:
You have 30 stickers.
Your friend gives 20 more.
Total = 50 stickers 🎉
Learn with an example
Add:
10 + 80 =
Notice that both numbers have 1 zero at the end. When the number of zeroes is the same, it is easy to add. First, arrange the numbers one above the other:
10 + 80 =
Next, add the zeroes. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero plus zero equals zero.
10 + 80 =__0
Now add the remaining digits. One plus eight is nine.
10 + 80 = 90
Add:
10 + 70 =_____
Notice that both numbers have 1 zero at the end. When the number of zeroes is the same, it is easy to add. First, arrange the numbers one above the other:
10 + 70 =_______
Next, add the zeroes. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero plus zero equals zero.
10 + 70 = 10
Now add the remaining digits. One plus seven is eight.
10 + 70 = 80
Add:
60 + 10 =____
Notice that both numbers have 1 zero at the end. When the number of zeroes is the same, it is easy to add. First, arrange the numbers one above the other:
60 + 10 =___
Next, add the zeroes. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero plus zero equals zero.
60 + 10 = 0
Now add the remaining digits. Six plus one is seven.
60 + 10 = 70
Let’s practice!🖊️
