Lesson 2.112.11 · Part II
Start hereWords, worked example, and sentence starters
Learning target I can add and subtract decimals by lining up the place values and the decimal points.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| DecimalSpanish: Decimal | A number with a dot, like 0.5, that shows a part less than one. | 3.75 means 3 ones + 7 tenths + 5 hundredths — it is between 3 and 4 |
| Place valueSpanish: Valor posicional | What a digit is worth based on where it sits in a number. | In 4.38: the 4 = 4 ones, the 3 = 3 tenths (0.3), the 8 = 8 hundredths (0.08) |
| TenthsSpanish: Décimas | The first spot after the decimal point. It shows parts out of 10. | 0.7 = 7/10 — like 7 slices of a pizza cut into 10 equal slices |
| HundredthsSpanish: Centésimas | The second spot after the decimal point. It shows parts out of 100. | 0.05 = 5/100 — like 5 pennies out of a dollar (100 pennies) |
| Annex zerosSpanish: Agregar ceros | Adding zeros at the end of a decimal so numbers line up evenly. | 15.7 becomes 15.70 so you can subtract 15.70 − 8.36 with aligned place values |
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
Word bank DecimalPlace valueTenthsHundredthsAnnex zeros
Watch outA common mistake
A common mistake in Add and Subtract Decimals is lining up the last digits (the right edges) of each number instead of lining up the decimal points — for example, adding 8.3 and 2.45 as if the 3 and the 5 belong in the same column. Before you add or subtract, add zeros so every number has the same number of decimal places (write 8.3 as 8.30), then check that the decimal points sit directly above one another.
Lesson 2.112.11 · Part II
Apply Day · Version ASupported practice
Learning target I can add and subtract decimals by lining up the place values and the decimal points.
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1Complete each step, then write the final answer.
Find 3.2 + 4.65.
Show your workHint Write 3.2 as 3.20. Line up the decimal points. Then add.
Final answer: -
2Complete each step, then write the final answer.
Find 14.6 + 3.25.
Show your workHint Write 14.6 as 14.60. Line up the decimal points. Then add.
Final answer:
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3Complete each step, then write the final answer.
Find 8.75 − 2.4.
Show your workHint Write 2.4 as 2.40. Line up the decimal points. Then subtract.
Final answer:
Lesson 2.112.11 · Part II
Apply Day · Version BCore practice
Learning target I can add and subtract decimals by lining up the place values and the decimal points.
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1Complete each step, then write the final answer.
Find 0.6 + 0.47.
Show your workFinal answer: -
2Complete each step, then write the final answer.
Find 36.7 + 8.56.
Show your workFinal answer:
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3Complete each step, then write the final answer.
Eva adds 3.4 + 1.25. She lines up the last digits and gets 1.59. What is the correct sum?
Show your workFinal answer:
Lesson 2.112.11 · Part II
Apply Day · ChallengeExtension
Learning target I can add and subtract decimals by lining up the place values and the decimal points.
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1Circle the letter of the best answer. Show how you know.
Find 12.4 + 3.75.
- A4.99
- B15.15
- C16.15
- D16.79
Line up the place values
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2Complete each step, then write the final answer.
Raj says 6 − 2.35 is 4.35. He subtracted the ones and copied the .35. What is the correct difference?
Show your workFinal answer: -
3Complete each step, then write the final answer.
Find 50 − 23.47.
Show your workFinal answer: