Unit 4, Lesson 22
Solve Problems Involving Large Numbers
Grade 4
Activity 2
Your teacher will give you and your partner a set of 10 cards, each with a number between 0 and 9. Place the cards facedown in a stack.
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Draw 3 cards. Use all 3 cards to form 2 different numbers that would give:
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the greatest possible sum
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the least possible sum
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the greatest possible difference
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the least possible difference
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Shuffle the cards and draw 4 cards. Use them to form 2 different numbers that would give:
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the greatest possible sum
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the least possible sum
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the greatest possible difference
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the least possible difference
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Student Section Summary
We used our understanding of place value and expanded form to add and subtract large numbers using the standard algorithm.
We learned how to use the standard algorithm to keep track of addition of digits that result in a number greater than 9.
When there are 10 in a unit, we make a new unit. Then record the new unit at the top of the column of numbers in the next place to the left.
When we subtract numbers, it may be necessary to decompose tens, hundreds, thousands or ten thousands before subtracting.
Finally, we learned if the digit we are subtracting is a zero, we may need to decompose one unit of the digit in the next place to the left.
Sometimes it is necessary to look two or more places to the left to find a unit to decompose. For example, here is one way to decompose a ten and a thousand to find .