TEACHERS: Sue Larson / SUBJECT:Understanding Decimal Notation
STANDARD:
  • 4.NF.C.6Use decimal notation for fractions with denominators of 10 or 100.

OBJECTIVE (EXPLICIT):
  • TSW identifyand compare decimals to hundredths by using representations on decimal squares. Students will write decimals through hundredths in standard form.

EVIDENCE OF MASTERY (MEASURABLE): TSW complete the objective above, with 80% accuracy.
SUB-OBJECTIVES, SWBAT (SEQUENCED FROM BASIC TO COMPLEX):
  • identifytenths, hundredths grids
  • read a number written in decimal form to hundredths.

KEY VOCABULARY: decimal, hundredths, tenths grid,hundredths grid / MATERIALS: pencil, paper, decimal square grids
ENGAGE: TTW ask students the following questions to determine a starting point for the lesson:
What do you know about fractions?
What do you know about decimals?
Students will share their ideas about what they know about the concepts. The teacher will NOT tell whether the ideas are right or wrong but will gather information about depth of knowledge and student misconceptions.
BEFORE / TEACHER WILL:
  • Have the students working in groups of three or four.
  • Give the students two minutes to place the decimal squares so everyone can see them.
  • Give the students two more minutes to answer the question, “What do you notice about the squares.”
• Ask, “Is 1/10 or 1/100 bigger? Why”
• Make the connection between .01
representing 1/100 of a dollar.
• Show place value notation starting
with the decimal point and writing
ones, tens, hundreds to the left of the
decimal point. Ask, “How many ones
make a ten? How many tens make a
hundred?”
• Ask the students, “What would it take
ten of to make a one?”
• Confirm that 10/10 would be 1 using
a picture.
• Show notation that 1/10 is written .1
• Have students look at 10/100 on the
green decimal square and show that
it is written as .10
• Ask students to find a yellow decimal
square that has the same amount
shaded as 10/100.
• Explain the difference between
hundreds and hundredths.
• Ask, “What would one thousandth
look like? “Ask a student to explain
thedifference between .001 and .100 / STUDENT WILL:
  • Get into groups
  • Place the decimal squares on desktops face up so they can see what is shaded on each square.
  • Respond to the teacher’s question about what they notice. (There are three different colors; represent 10, 100, or 1000 pieces; different parts are shaded and not shaded)
  • Reply 1/10 because it is a bigger piece.
  • Answer teacher questions.
  • Watch and answer questions. Ten ones make a ten. Ten tens make a hundred.
  • Students discuss and reply that it takes ten tenths to make a one.
  • Watch the picture.
  • Watch the notation.
  • Watch the notation.
  • Students hold up the yellow decimal square with one row shaded.
  • Listen.
  • Reply that it is a yellow square with one itty-bitty pieces shaded. It is written .001. A yellow square with one row shaded or 100 itty bitty pieces is .100

DURING / TEACHER WILL:
  • Gather students around a group to model how to play the game NAME IT (See attachment at end of lesson)
  • Ask for any clarifying questions from the students.
  • Make sure all materials are available and readily accessible for the students.
  • Allow the students enough time to play the game with their group.
  • Circulate the room and ask questions of the students as they work.
/ STUDENT WILL:
  • Watch as the game is modeled.
  • Ask any questions, if needed, before they begin.
  • Follow the rules and expectations given to them, by playing the math game.
  • Answer questions asked of them by the teacher.

Questions to ask as the teacher circulates:
“Is this a tenth, hundredth, or thousandth square? How do you know?”
“What is the first place after the decimal point? Why?”
“What is the second place after the decimal point? Why?
“How many of the pieces are shaded? What size pieces are they? How would I write that as a number.”
“Is there a way you can tell whether a number is bigger or smaller just by looking at the decimal?”
“Which is bigger .9 or .15? Why?”
AFTER / TEACHER WILL:
  • Call back the students so that they are ready to listen.
  • Ask, “How many people think they might know how to draw a decimal if I write it. Let’s see. Using a piece of paper, draw me a picture for .23”
  • Ask the question: “What did you learn today?” (Allows them time to discuss with their partner.) Call on students to answer as time allows.
  • Prompt the students to complete this question independently, on a piece of paper to be collected: “Compare .25 and .52.”
/ STUDENT WILL:
  • Give the teacher their attention.
  • Raise their hands if they think they know the answer. Draw a picture with 100 squares and 23 of them shaded.
  • Answer the question. Share with a partner. Share with the class if called upon by the teacher.

Name It!

1)Have the students gather around and have one group of three or four students model the game.

2)Decimal squares are placed face down in the center of the group. A person is chosen to start.

3)The first person turns over the top decimal square and states whether the square represents tenths (red), hundredths (green), or thousandths (yellow).

4)That person then counts the number of pieces that are shaded.

5)The player then tells the number of spaces after the decimal point that the square would represent (tenths – one space, hundredths – two spaces, thousandths – three spaces).

6)The person then writes or says aloud the standard form for the decimal square. Ex. Red square three rows shaded is three tenths or .3

Green square with two rows and five boxes shaded is twenty-five

hundredths or .25.

7)If the person is correct, the player keeps the square. If the person is incorrect, place the card at the bottom of the pile.

8)Play then goes to the next person.

9)When time is called, the person with the most number of squares wins.