Adding and subtracting

PROCEDURAL

Mathematics›Addition & Subtraction|Ages 5—6|ID: mt_mr_Vk7FGzK

Add and subtract one-digit and two-digit numbers to 20, including zero

Mastery Evidence

Calculate 14 + 5 = 19
Calculate 17 – 3 = 14
Add or subtract 0 and explain the result stays the same

Assessment Prompt

“Can [child] work out sums like '14 + 5' or '18 − 6' in their head or on paper, and do they know that adding or taking away zero leaves the number unchanged?”

Curriculum Standards1 alignment

Maths/Y1/AS/3The national curriculum in England

Add and subtract within 20

Add and subtract one-digit and two-digit numbers to 20, including zero.

Mathematics · Key Stage 1

Prerequisites1

Number bonds
hardAges 5—6

Show full prerequisite tree

Number bonds hard
Adding/subtracting to 20 procedurally requires knowing the number bonds
- Number bonds to 9 hard
  Number bonds within 20 builds on knowing bonds to 10
  - Numbers up to 10 into pairs hard
    Making 10 is a specific application of decomposing numbers into pairs
    - Addition as combining or putting together two hard
      Decomposing numbers into pairs requires understanding addition as combining
      - How Many in Total? hard
        Understanding addition as combining groups requires knowing numbers represent quantities (cardinality)
        
        One-to-one counting hard
        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'
- Fluent adding and subtracting within 5 hard
  Recalling bonds within 20 builds on fluency within 5
  - Addition as combining or putting together two hard
    Fluency with addition within 5 requires understanding addition as combining
    - How Many in Total? hard
      Understanding addition as combining groups requires knowing numbers represent quantities (cardinality)
      - One-to-one counting hard
        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'
  - Subtraction as taking away or separating hard
    Fluency with subtraction within 5 requires understanding subtraction as taking away
    - How Many in Total? hard
      Understanding subtraction as taking away requires knowing numbers represent quantities (cardinality)
      - One-to-one counting hard
        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

Unlocks2

Mental addition and subtraction (age 6+)
hardAges 6—7
Early Word Problems
hardAges 5—7