Lesson 2.112.11 Small Group · Group 1
Group 1 · Set BSecond form · new problems, same idea
Learning target With my small group, I can add and subtract decimals by lining up the place values and the decimal points — one step at a time, with support.
Remember2.11 Small Group · Group 1
Line up the decimal points, write zeros so the numbers have the same places, then add or subtract like whole numbers. To add or subtract decimals, line up the decimal points so the same place values match.
Words: Decimal (Decimal)Place value (Valor posicional)Tenths (Décimas)Hundredths (Centésimas)Annex zeros (Agregar ceros)
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1Complete each step, then write the final answer.
Find 36.7 + 8.56.
Show your workHint Write 36.7 as 36.70. Line up the decimal points. Then add.
Final answer:
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2Complete each step, then write the final answer.
Sam has 5.6 liters of water. He adds 2.35 liters. How many liters does he have now?
Show your workHint Write 5.6 as 5.60. Line up the decimal points. Then add.
Final answer: -
3Complete each step, then write the final answer.
A pencil costs $0.65. A pen costs $1.40. How much more does the pen cost?
Show your workHint Subtract the smaller cost from the larger cost. Line up the decimal points.
Final answer: -
4Complete each step, then write the final answer.
Find 20.4 − 7.86.
Show your workHint Write 20.4 as 20.40. You will need to regroup more than once, even across a zero.
Final answer:
Explain your thinkingWhy do we line up the decimal points and not the last digits? Use Eva's mistake to explain.
Sentence starter I line up the decimal points so that ___. · Eva got 1.59, but the sum is ___ because ___.