Let’s Learn!
Which addition tools and strategies do we know?
Goal:
Goal:
Think About It!
Goal: How do we write a two-digit addition sentence?
How much candy do Ella and Lucas have?
8 and 15 are our addends. We add them together to find the sum. Here is our addition sentence:
8 + 15 = ?
Let’s add 8 + 15 using an addition strategy. Addition strategies help us add. Today we’ll focus on using base-ten blocks, number lines, and ten frames.
Base-ten blocks
Number-line
Ten-frames
Base-Ten Blocks
These are base-ten blocks. The small squares are called unit blocks. They are worth 1. The long sticks are called rods. They are worth 10. Add the rod and unit blocks together to find the sum!
8 + 15 = ?
Regroup 10 of the unit blocks into another rod.
How many rods and cubes do you see? Click Show Me to check your answer.
2 rods and 3 cubes make 23. That means 20 + 3 = 23.
Ten Frames
Place dots in the tens section for the larger addend. Then, we fill in the rest of the tens and ones sections with the smaller addend.
8 + 15 = ?
15 is the larger addend. Put 15 red dots in the tens section. 8 is the smaller addend. We’ll need to put 8 yellow dots in the tens and ones section. Click Show Me to add the yellow dots!
There are 20 dots in the tens section and 3 dots in the ones section. 20 + 3 is 23!
Number Line
Place a dot on the larger addend. Jump the same amount as the smaller addend. The sum is the number you land on!
8 + 15 = ?
Place a dot on 15 because it’s the larger addend. We need to jump 8 times. Click Show Me to add 8 on the number line!
The jumps landed on 23. That means 8 + 15 = 23!