Proving Number Know-How

Overview

Today’s lesson is a short placement diagnostic to see what students already know about representing, reading, writing, and ordering whole numbers to at least 120. Students use MAB/base-10 blocks, number lines, and expanded form, matching the way they will practise this unit over the week.

Learning intentions

• I can represent whole numbers to 120 using MAB/base-10 materials.
• I can read and write whole numbers to 120 using numerals.
• I can order whole numbers to 120 on a number line or chart.
• I can show expanded form for numbers to 120 (for example, 34 = 30 + 4).

Success criteria

• I can correctly make a number to 120 with base-10 blocks and explain what each part means.
• I can write the given number (to 120) when shown MAB/base-10 or a number line.
• I can put numbers in order (e.g. smallest to largest) up to 120.
• I can match a number to its expanded form for tens and ones.

Curriculum links

• Number — VC2M1N01: recognising, representing and ordering numbers to at least 120 using physical and virtual materials, numerals, number lines and charts.
• Number — VC2M1N02: partitioning one- and two-digit numbers in different ways, including tens and ones.
• Number — VC2M1N03: quantifying sets to at least 120 by grouping/skip counting (used briefly through tens/ones representations during the diagnostic).

Lesson structure (60 minutes)

1. 0–5 min · Welcome & purpose. Teacher explains this is a “show what you know” diagnostic and models using one example number (e.g. 47) with base-10 blocks and a number line jump to consolidate expectations.

• Students repeat the example actions at their seats (touch tens rods and ones cubes) and say the number name.

2. 5–10 min · Diagnostic instructions & routines. Teacher reviews how to move through tasks: read the prompt, show with blocks, write the numeral, then check by pointing on the number chart/number line.

• Students practise one quick “check” with a teacher-written number on the board (choose the correct place on a 0–120 chart).

3. 10–35 min · Core diagnostic: represent to 120. Students rotate through the diagnostic stations (or complete a single worksheet pack, based on your school approach). The tasks assess reading, writing, ordering, and representation to 120 using:

• MAB/base-10 blocks for tens and ones
• 0–120 number chart for locating numbers
• number line strips (0–120 with marked tens and selected ones)
• expanded form for tens and ones (writing the number as (tens) + (ones)) Teacher action: circulate to note strategies and misconceptions (e.g. counting in ones instead of tens, reversing tens and ones, misplacing numbers on the chart).
• Students work independently or with brief teacher prompts only when stuck long enough to lose confidence.

4. 35–45 min · Quick whole-class debrief (spot common errors). Teacher selects 2–3 anonymised examples from student work (or teacher questions) and asks: “What is the number? What tens and ones do you see? Where would it be on the number line?”

• Students answer using hand signals or quick verbal explanations, then correct one item together on the board.

5. 45–55 min · Personalise follow-up & record. Teacher gives each student a “next step” choice based on diagnostic results:

• Group A (secure): order and locate numbers on a chart/number line using given cards.
• Group B (developing): build and write numbers using base-10 blocks, then match to expanded form.
• Group C (support): use teacher-guided tracing on the number line and tens/ones regrouping support.
• Students complete the targeted follow-up activity (short, focused) and record one strategy in their workbook (for example: “I made 36 as 3 tens and 6 ones.”).

6. 55–60 min · Exit ticket (one check). Each student completes one final item: represent a two-digit number to 120 with base-10 blocks OR place it correctly on a number line; then write the expanded form.

• Students submit the exit ticket for immediate sorting into next lesson groups.

Resources

• Ochre Foundation/Year 1 place value diagnostic tasks (adapt range upward for your class needs)
• Base-10/MAB place value materials (tens rods and ones cubes or flats)
• 0–120 number chart (one per student or shared at table)
• Number line strips (0–120), with tens labelled
• Diagnostic worksheet pack: represent, write, order, expanded form
• Small whiteboards and markers (for whole-class debrief and quick checks)
• Clipboards, pencils, and erasers
• Timer and station labels (optional, if using rotations)

Assessment

• Teacher observation during the diagnostic: whether students can correctly link tens/ones to numerals and locate numbers to 120.
• Marking of diagnostic items: correct numeral, correct placement on chart/number line, and correct expanded form.
• Exit ticket: accuracy on one representation plus expanded form (tens and ones correctly identified).

Differentiation

• Support:
• Provide sentence starters: “I made ___ as __ tens and __ ones.”
• Use a partially completed expanded form frame: __ tens + __ ones.
• Offer a teacher-guided example for students who stall (point to the tens rod, then the number chart).
• Extension (for students who finish early, as specified):
• “How high can you prove it?” challenge: represent numbers to 500 using base-10 blocks (flats), write them in expanded form, and justify the strategy with a partner (e.g. “I know it’s 2 hundreds because I used 2 flats.”).
• EAL/SEN:
• Keep directions short and use gestures (build → write → point).
• Offer picture supports for “tens/ones” and “hundreds” in the extension challenge.

Extension (optional)

None beyond the specified early-finish challenge.