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Foundation + Year 1

Number Sequence

Identify what comes before, after, and between numbers in the counting sequence.

In a nutshell

ENSSA assesses children’s ability to use the ordered number sequence through the Missing Number task. Children identify the missing numeral in a counting sequence, drawing on their knowledge of number words, written numerals, and what comes before, after, or between other numbers.

Children first develop a stable counting sequence with small numbers, typically within 10, before extending this knowledge to larger ranges, teen numbers, and transitions across decades.

In Foundation, students identify missing numbers within 20 using counting, visual supports, numeral recognition, and emerging understanding of teen numbers as 10 and some more.

By Year 1, students increasingly use number order, counting patterns, and developing tens-and-ones place-value knowledge to identify missing numbers efficiently within 100.

The main instructional goal is for students to know and use the ordered number sequence, not simply to recite the count list from the beginning. Students should learn to answer questions such as “What comes after 17?”, “What comes before 30?”, “What number is between 45 and 47?”, and “What number is missing?”

Complete number lines are not the main representation for Missing Number tasks. Number tracks, number paths, number lists, number cards, and hundreds charts are usually more useful because they make the count sequence visible.

This guidance is designed for classes where ENSSA results indicate a class-wide need to strengthen number order, missing-number knowledge, or before/after/between language.

See also: Magnitude Comparison and Magnitude Estimation

Teaching guidance

For schools and teachers using Ochre curriculum materials

Choose the curriculum used by your school, then find the relevant Foundation or Year 1 resource.

This section is for teachers using Ochre units as part of Tier 1 mathematics instruction in Victorian Curriculum settings, including MACS and CESL schools.

Use Ochre unit lessons when students need teaching or reteaching. Use Ochre Daily Review when students have already been taught the skill and need practice, reactivation or fluency-building.

Step 1: Where does this sit in your teaching sequence?

If

The skill has not yet been taught and is coming up soon

Then

Let the scheduled Ochre lesson address it. Consider brief pre-teaching for students flagged by ENSSA.

If

The skill has not yet been taught and is scheduled much later this year

Then

Consider bringing the relevant lesson section forward for flagged students only — check prerequisite lessons first.

If

The skill has already been taught

Then

Go to Step 2 below.

If

The skill was taught a while ago, last term or last year

Then

Start with Daily Review as a quick reactivation and accuracy check. If students are still inaccurate, go to Step 2.

Step 2: How are students performing right now?

Use this once you’ve confirmed the skill has already been taught.

If

Students are inaccurate or unsure

Then

Use the Ochre unit lesson section first — not Daily Review.

If

Most students are inaccurate

Then

Reteach the relevant modelling/guided-practice section to the whole class.

If

A few students are inaccurate but most are secure

Then

Use the lesson section for small-group reteaching with flagged students only.

If

Students are accurate but slow or inconsistent

Then

Use Daily Review — do not run a full reteach.

Foundation

Build foundations for this skill.

3 resources
Unit Plan FN03V Counting and place value 2Use this when Foundation students are inaccurate or unsure with forward/backward sequence, missing numbers, one more/one less, or ordering within 20.
Open Ochre Foundation Mathematics page ↗
After logging in, look for

FN03V Counting and place value 2

Skill link

Supports number sequence through number tracks to 20, one more/one less, missing numbers and ordering.

Best section to use

Number-track, missing-number, one more/one less and ordering lesson sections.

If…then decision
  • If students rely on counting from 1 → use number-track modelling and one more/one less sections.
  • If students skip numbers in a sequence → use missing-number lesson sections.
  • If students can say the count sequence but cannot locate numbers → use number-track activities.
Unit PlanExtension FN06V Counting and place value 3, Lessons 1–2Use this when students are mostly secure with basic sequence to 20 but need more explicit work with before, after and between.
Open Ochre Foundation Mathematics page ↗
After logging in, look for

FN06V Counting and place value 3, Lessons 1–2

Skill link

Extends number sequence to ordinal position, before/after/between and position on a number track.

Use with care

This is an extension/bridge resource. Do not use before students have basic number sequence knowledge.

Daily Review Number–Place Value Daily Review deckUse this when students have already been taught the number sequence skill and need reactivation or fluency.
Open Ochre Foundation or Year 1 Mathematics page ↗
After logging in, look for

Daily Review Topic Deck: Number – Place Value

Skill link

Practice with counting, missing numbers, before/after/between, ordinal position and ordering.

Use with care

Do not use when students are consistently inaccurate — return to the relevant unit lesson section first.

Year 1

Extend this skill through Year 1.

3 resources
Unit Plan 1N03V Counting and place value 2, Lessons 5–7Use this when Year 1 students need reteaching with two-digit before/after relationships, especially around decade transitions.
Open Ochre Year 1 Mathematics page ↗
After logging in, look for

1N03V Counting and place value 2, Lessons 5–7

Skill link

Supports Year 1 number sequence through one more, one less, and applying one more/less to two-digit numbers.

Best section to use

Lessons 5–7.

Unit Plan 1N01V Counting and place value 1, Lessons 12–13Use this when students need explicit teaching with hundred-chart patterns, number location, decade transitions or number-line sequence to 100.
Open Ochre Year 1 Mathematics page ↗
After logging in, look for

1N01V Counting and place value 1, Lessons 12–13. Note: this unit may currently appear under a Year 2 filename — check the unit content and look for 1N01V, not the file title.

Skill link

Supports Year 1 number sequence through locating numbers on a 100 chart and locating numbers to 100 on a number line.

If…then decision
  • If the difficulty is one more/one less with two-digit numbers → use 1N03V Lessons 5–7 instead.
  • If the difficulty is locating numbers on a 100 chart or number line → use this card.
Daily Review Number–Place Value Daily Review deckUse this when students have already been taught the number sequence skill and need reactivation or fluency.
Open Ochre Foundation or Year 1 Mathematics page ↗
After logging in, look for

Daily Review Topic Deck: Number – Place Value

Skill link

Practice with counting, missing numbers, before/after/between, ordinal position and ordering.

Use with care

Do not use when students are consistently inaccurate — return to the relevant unit lesson section first.

Coming soon

Intervention resources (Tier 2 & Tier 3)

Targeted supports for students or small groups when classwide teaching is not enough.