Decimal place value

PROCEDURAL

Mathematics›Fractions|Ages 8—9|ID: mt_Fl7b8q9pI1

Round decimals with one decimal place to the nearest whole number

Mastery Evidence

Round 3.7 to 4 and 3.2 to 3
Place 6.5 on a number line between 6 and 7 and decide it rounds to 7
Round a set of one-decimal-place numbers and explain the rounding rule

Assessment Prompt

“If [child] measures something as 3.7 m, can they tell you whether that rounds to 3 m or 4 m — and explain why?”

Prerequisites1

Decimal equivalents of tenths and hundredths
hardAges 8—9

Show full prerequisite tree

Decimal equivalents of tenths and hundredths hard
Must understand decimal notation to round decimals
- Tenths (age 8+) hard
  Must understand hundredths before writing decimal equivalents
  - Tenths hard
    Count in tenths is prerequisite to extending to hundredths
    - Fractions of amounts hard
      Tenths extend fraction understanding from halves, thirds, quarters
      - Finding halves and quarters (age 5+) hard
        Working with 1/4, 2/4, 3/4 extends from Y1 understanding of quarters
        
        What Is a Half? hard
        Understanding quarters extends from understanding halves — both are equal parts but quarters requires dividing into 4
        
        Division as equal sharing hard
        Finding a half requires equal sharing into 2 groups — a division concept
        
        Subtraction as taking away or separating hard
        Division as equal sharing/grouping requires understanding subtraction as taking away/separating
        
        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'
      - What Is a Half? hard
        Working with fractions extends from Y1 understanding of halves
        
        Division as equal sharing hard
        Finding a half requires equal sharing into 2 groups — a division concept
        
        Subtraction as taking away or separating hard
        Division as equal sharing/grouping requires understanding subtraction as taking away/separating
        
        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'
      - Division as equal sharing soft
        Finding fractions of quantities uses equal sharing (division)
        
        Subtraction as taking away or separating hard
        Division as equal sharing/grouping requires understanding subtraction as taking away/separating
        
        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'
      - Fraction Notation hard
        Writing fractions like 1/3 and 3/4 requires knowing numerator and denominator
    - Counting in 2s soft
      Skip counting supports counting in tenths
      - Rote counting to 100 hard
        Skip counting in 2s, 5s, 10s requires fluent rote counting by ones first
        
        One-to-one counting hard
        One-to-one correspondence requires knowing the number name sequence
- Decimal & Percent Notation hard
  Writing decimal equivalents of tenths and hundredths requires decimal point and place-value vocabulary

Unlocks1

Decimal place value (age 9+)
hardAges 9—10