In this unit, children extend their understanding of place value, which provides a foundation for the development of strategies for fluently adding and subtracting multi-digit numbers later in second grade. They also explore standard tools and units for measuring length and time. The following big ideas will be covered in this unit:
- An analog clock is used to tell time to the nearest five minutes.
- The three digits of a 3-digit number represent amounts of hundreds, tens and ones.
- Place value determines which numbers are larger or smaller than other numbers. (three digit numbers)
- The groupings of ones, tens and hundreds can be taken apart in different but equivalent ways. For example 356 can be decomposed into 3 hundreds 5 tens and 6 ones or 2 hundreds 15 tens and 6 ones.
- The smaller the unit, the more units it will take to measure the length of an object.
- Numbers on a ruler indicate the spaces (distance) between the marks.
- To measure something:
- You have to decide on the attribute to be measured. (For ex. length)
- Select a unit that has that attribute. (For ex. inches)
- Compare the units by matching with the attribute of the object
- Inches, feet and centimeters are standard units of measurement.
Number & Operations in Base Ten
2.NBT.A. Understand place value.
2.NBT.A.1. Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases:
2.NBT.A.1a. 100 can be thought of as a bundle of ten tens — called a “hundred.”
2.NBT.A.1b. The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three, four, five, six, seven, eight, or nine hundreds (and 0 tens and 0 ones).
2.NBT.A.2. Count within 1000; skip-count by 5s, 10s, and 100s.
2.NBT.A.3. Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.
2.NBT.A.4. Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons.
2.NBT.B. Use place value understanding and properties of operations to add and subtract.
2.NBT.B.5. Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.B.7. Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
2.MD.A. Measure and estimate lengths in standard units.
2.MD.A.1. Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
2.MD.A.2. Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
2.MD.A.3. Estimate lengths using units of inches, feet, centimeters, and meters.
2.MD.C. Work with time and money.
2.MD.C.7. Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m.
2.MD.D. Represent and interpret data.
2.MD.D.9. Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.
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Students will have opportunities to:
- Make sense of their problem (MP.1)
- Reflect on their thinking as they solve their problem (MP.1)
- Keep trying when the problem is hard (MP.1)
- Check whether their answer makes sense (MP.1)
- Solve problems in more than one way (MP.1)
- Compare their strategies with others (MP.1)
- Explain their mathematical thinking clearly and precisely (MP.6)
- Use an appropriate level of precision for their problem (MP.6)
- Use clear labels, units, and mathematical language (MP.6)
- Think about accuracy and efficiency when they count, measure, and calculate (MP.6)
- The length of time can be measured using standard units such as, seconds, minutes, hours, and days.
- An analog clock is used to tell time to the nearest half hour and hour.
- Numbers can be represented in many ways, such as with pictures, number lines and expanded form.
- The two digits of a 2-digit number represent amounts of tens and ones.
- Place value determines which numbers are larger or smaller than other numbers. (two digit numbers)
- The groupings of ones and tens can be taken apart in different but equivalent ways. For example 56 can be decomposed into 5 tens and 6 ones or 4 tens and 16 ones.
- Multi-digit numbers can be built up or taken apart in a variety of ways. These parts can be used to create estimates in calculations rather than using the exact numbers involved. (three digit numbers)
- Flexible methods of computation for addition and subtraction involve decomposing and composing numbers in a variety of ways. (three digit numbers)
- Yards and meters are standard units of measurement.
- Line plots are useful tools for collecting data because they show the number of things along a scale
24-Hour timeline, A.M; P.M., analog clock, base-10-blocks, centimeter (cm), cube, flat, long, digital clock, digit, estimate, expanded form, foot (ft.), hour, hour hand, inch (in), is greater than, is less than, metric system, minute, minute hand, represent, ruler, standard unit, U.S. customary system.
Bold: Listed in teacher's EDM4 edition
Normal Font: not listed in teacher’s edition as a vocabulary word but will be helpful for students in explanations
The following lesson plan sequence is obtained from Everyday Mathematics 4. Each lesson is aligned with a learning objective to inform the teachers on what students should be able to at the end of the lesson. The student objective informs the students of their learning goals for the day and it should be reviewed before, during and at the end of the lesson. Each lesson includes a mathematics task that should be implemented to meet the learning objectives. Teachers can select from the practice opportunities to reinforce the learning goals of the day.
The following language supports are for English Language Learners but could also be used to support any struggling learner in mathematics. The strategies are obtained from the SIOP model. The language objectives will support students' academic language development. The sentence stems and starters provides the support many students need to be able to participate in discussions and writing about mathematics.