IM U5 L4 Adding and Subtracting Decimals with Many Non-Zero Digi

Adding and Subtracting Decimals with Many Non-Zero Digits

Lesson 4 Unit 5

Let’s practice adding and subtracting decimals.

Today’s Goals

I can solve problems that involve addition and subtraction of decimals.

Subject | Subject

Some text here about the topic of discussion

Warm-Up pg 35

Open Ended

Here are three ways to write a subtraction calculation. What do you notice? What do you wonder?

Poll

Clare bought a photo for 17 cents and paid with a $5 bill. Look at the previous question. Which way of writing the numbers could Clare use to find the change she should receive?

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Find the amount of change that Clare should receive. Show your reasoning, and be prepared to explain how you calculate the difference of 0.17 and 5.

Decimals All Around

Page 36

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Find the value of each expression. Show your reasoning in your book.

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Find the value of each expression. Show your reasoning in your book.

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Find the value of each expression. Show your reasoning in your book.

Open Ended

Which method or methods did you use in the previous question? Why?

In what ways were your methods effective? Was there an expression for which your methods did not work as well as expected?

Fill in the Blank

Lin’s grandmother ordered needles that were 0.3125 inches long to administer her medication, but the pharmacist sent her needles that were 0.6875 inches long. How much longer were these needles than the ones she ordered?

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There is 0.162 liter of water in a 1-liter bottle. How much more water should be put in the bottle so it contains exactly 1 liter?

Open Ended

One micrometer is 1 millionth of a meter. A red blood cell is about 7.5 micrometers in diameter. A coarse grain of sand is about 70 micrometers in diameter. Find the difference between the two diameters in meters. Show your reasoning

Missing Numbers

Fill in the Blank

Write the missing digits in each calculation so that the value of each sum or difference is correct.​

Fill in the Blank

Write the missing digits in each calculation so that the value of each sum or difference is correct.​

Fill in the Blank

Write the missing digits in each calculation so that the value of each sum or difference is correct.​

Fill in the Blank

Write the missing digits in each calculation so that the value of each sum or difference is correct.​

Fill in the Blank

Write the missing digits in each calculation so that the value of each sum or difference is correct.​

Lesson Synthesis

• Which problems did you solve with addition (or subtraction)? How did you know to use addition (or subtraction)?

• How did you find the sums or differences? Why did you chose this method?

• Did you use the same method for all of your problems? Why or why not?

• When subtracting a number with fewer decimal places by another number with more decimal places, such as 2.4 – 0.1587, what strategies might be helpful.

Let's Bring it together

Taller and Farther

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Diego is 59.5 inches tall. His brother is 40.125 inches tall. How much taller than his brother is Diego?

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A runner has run 1.192 kilometers of a 10-kilometer race. How much farther does he need to run to finish the race?