Addition and Subtraction Party Mix !
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Do Now
Everybody writes
Do Now
1 hundred = ___ tens
1 ten = ____ ones
Difference
Big Ideas Review
What do we already know about the US Algorithm?
A ten can be decomposed into ten ones.
Big Idea #1
Ten ones can be composed into one ten.
When exchanging between place values, the units may change, but the overall value stays the same.
Big Idea #2
A hundred can be decomposed into ten tens.
Big idea #3
Ten tens can be composed into one hundred.
Big idea #4
When there is a zero in a place, no value can be borrowed from it. Instead, value must be borrowed from the next greatest place with value.
Example # 1
Let's add:
345 + 678
US Addition Algorithm
Example #2
Let's subtract:
504- 126.
US Subtraction Algorithm
Place Value Chart
Checkpoint !
So what are some key things we should remember when using the US Algorithms ?
CFU
Line up place values
Move from lesser place on the right to the greater place on the left
Value can be moved between places
Try these examples!
Guided Practice
1. 594 + 287 =
2. 307 - 259 =
3. 415 + 978=
4. 1,000 - 584=
Time to check your answers!
Check, Check !
Great Work Mathematician!
2. 307- 259 = 48
1. 594 + 287 = 881
3. 415 + 978= 1,393
4. 1,000 – 584= 416
Your turn!
You will have 15 minutes to practice adding and subtracting numbers using the US algorithm. Then, move on to your story problem.
Let’s see who is going to crush it! You got it!
Independent Practice
iSpot it!
Game
Your turn!
Exit Ticket
Over the course of the day we reviewed a lot! We reviewed how to add and subtract numbers! Now you get to show what you know on your exit ticket!
Topic
Continue to love math!