Decimal place value (age 9+)

PROCEDURAL

Mathematics›Fractions|Ages 9—10|ID: mt_Ii1hV4V5ql

Round decimals with two decimal places to the nearest whole number and to one decimal place

Mastery Evidence

Round 3.47 to the nearest whole number (3) and to 1 d.p. (3.5)
Round 12.95 to 1 d.p. (13.0) and explain the boundary case
Estimate 4.83 + 2.17 by rounding each to the nearest whole number

Assessment Prompt

“If [child] measures a length as 4.67 m, can they round it to the nearest whole metre — and also to the nearest tenth of a metre?”

Prerequisites1

Decimal place value
hardAges 8—9

Show full prerequisite tree

Decimal place value hard
Rounding 1dp to whole (Y4) is prerequisite to rounding 2dp to whole or 1dp
- 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

Decimals to three places
softAges 9—10