Building Decimal Parts

Overview

Lesson 1 of 5 in Decimal Place Value Explorers. Students use paper strips, grids and fraction tiles to partition one whole into tenths and hundredths, then connect these models with fraction and decimal notation.

Learning intentions

• WALT create and represent tenths and hundredths by dividing a whole into 10 or 100 equal parts.
• WALT connect unit fractions to decimal notation.
• WALT read and write tenths and hundredths as fractions and decimals.
• WALT explain how hundredths are made by dividing a whole into 100 equal parts.

Success criteria

• I can model tenths and hundredths using materials or diagrams.
• I can write matching fraction and decimal representations.
• I can explain that one tenth is 0.1 and one hundredth is 0.01.
• I can explain that hundredths are made by dividing a whole by 100.

Curriculum links

• Number: understand, represent and compare fractions and decimals.
• Number: use place-value structure to connect tenths and hundredths with decimal notation.
• Mathematical practices: use materials, diagrams, symbols and mathematical language to communicate reasoning.
• Mathematical inquiry: notice patterns, make connections and explain how representations show the same quantity.

Lesson structure (30 minutes)

1. 0–4 min – Daily review and learning goal Display the WALT and ask students to answer on mini-whiteboards: What is 1 whole? How many tenths make one whole? Which is greater: 3/10 or 7/10? Open with the review and learning-goal slides and briefly discuss the reasoning, not just the answers.

2. 4–9 min – Build tenths with strips Give each pair a paper strip representing one whole. Ask students to fold or mark it into 10 equal parts, label each part 1/10, and shade 3/10. Use the fraction wall and strip cards as a visual comparison. Connect one tenth to the decimal notation 0.1 using a place-value chart.

3. 9–14 min – From tenths to hundredths Show that each tenth can be divided into 10 smaller equal parts, creating 100 parts altogether. Students use a 10-by-10 grid to shade one hundredth and four tenths. Ask: How many hundredths are in one tenth? Record 1/10 = 10/100 = 0.1 and 1/100 = 0.01. Use the tenths-and-hundredths modelling slides for the visual demonstration.

4. 14–22 min – Partner representation task Distribute the tenths and hundredths representation worksheet to pairs or individuals. Students represent given amounts using a grid, fraction and decimal, such as 2/10, 7/10, 12/100 and 35/100. They explain one answer to their partner using the sentence stem: “I know this is ___ because…”. Circulate and question students about equal parts and the value of each digit.

5. 22–27 min – Share and compare Select two or three examples to discuss. Include a tenths example and a hundredths example. Ask: Which is greater, 0.3 or 0.27? How can the grid or equivalent hundredths help us decide? Reinforce that 0.3 is the same as 30/100. Return to the discussion and comparison slides.

6. 27–30 min – Exit explanation Students complete the final prompt on the reflection and exit section: “Show 0.06 as a fraction and explain what the 6 means.” Invite two students to share. Revisit the success criteria and identify any learners needing a guided revisit in the next lesson.

Resources

• the Decimal Place Value Explorers lesson deck
• the tenths and hundredths representation worksheet
• the fraction wall and strip cards
• Paper strips, one per pair
• 10-by-10 grids, one per student or pair
• Coloured pencils or highlighters
• Scissors and rulers
• Mini-whiteboards and pens
• Optional fraction tiles or base-ten materials
• Visual word bank: whole, equal parts, tenth, hundredth, fraction, decimal

Assessment

• Listen for accurate explanations during folding, shading and partner talk, especially whether students understand that all parts must be equal.
• Check worksheet representations for correct links between fractions, shaded models and decimals.
• Use the exit explanation to identify whether students understand that 0.06 represents six hundredths, not six tenths.

Differentiation

• Support learners with pre-partitioned strips and grids, a place-value chart, the visual word bank and guided teacher modelling. Work with a small group during the partner task.
• Pair learners strategically and provide sentence stems such as “The whole is divided into…” and “___ hundredths is equal to…”.
• For EAL and learners requiring additional support, use gestures, colour-coding and repeated oral rehearsal of “one tenth” and “one hundredth”; accept pointing or drawing before expecting a written explanation.
• Extend confident learners by asking them to represent the same amount in more than one way, such as 0.4 = 4/10 = 40/100, and explain why the representations are equivalent.