Module 2 Counting and understanding numbers
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Can I partition a two-digit number into tens and ones (units) and use this to create related addition and subtraction sentences?

Example review questions

  • Use some place-value cards to make 16. What is it made up of? How would you make 61?
  • If I partition these numbers into tens and ones, which has the most tens and which has the most ones?
    18, 27, 94, 56, 77
  • What two-digit number would these place value cards make?
    Two place value cards marked 8 and 60.
  • Which number goes into the empty box? Can you tell me without counting?
    Number line showing 20 + 8 = ?
  • Can you complete these number sentences? What do you notice?
    10 + 4 = empty box
    14 − empty box = 10
    14 = empty box + 4
    empty box − 10 = 4
  • What two-digit number is the same as six tens and four ones (units)?

Teaching guidance

This teaching guidance document suggests some of the key vocabulary, models, images and practical equipment that children should experience and be able to use. It also includes some teaching tips to provide a few starting points for ways of supporting children with this area of mathematics.

PDF file Can I partition a two-digit number into tens and ones (units) and use this to create related addition and subtraction sentences? - teaching guidance | 85KB new window

Consolidation and practice

These resources are to support children in guided or independent work.

PDF file ITP Guide | 4317KB new window

SWF file Place value ITP | 26KB new window

SWF file Beadsticks ITP | 204KB new window

XLS file Place value and partitioning tool spreadsheet | 132KB new window

PDF file Place value and partitioning tool spreadsheet guide | 527KB new window

PDF file Two-digit number follow me cards | 18KB new window

PDF file Partitioning and recombining models and images chart | 314KB new window

PDF file Year 2 Block A lesson notes | 1181KB new window

Opportunities to use and apply

Possible contexts include:

  • Word problems and puzzles, e.g. I had 45p and spent 40p on a pen. How much did I have left?
  • Dad baked some cakes and then our dog got into the kitchen and ate 10 of them! We've only got 7 left. How many cakes did Dad bake?
  • Can you fill in the missing numbers?
    90 + empty box = 94
    70 = empty box − 5
  • Reasoning about numbers, e.g. use a set of 0-9 number cards to make some two-digit numbers. What are the five largest two-digit numbers you can make?
  • Working out related number sentences, e.g. if you partition 23 into tens and ones what addition and subtraction number sentences can you make with the numbers?
  • Calculation, e.g. how can partitioning help you to add 37 and 23? What about 48 + 25?

Confirming learning

Ask probing questions such as:

  • What can you tell me about the digits in this number (14)? What about this number (41)? What is the same and what is different about these two numbers?
  • Complete these number sentences.
    10 = 16 − empty box; 16 − empty box = 6; 16 = 10 + empty box; 10 + empty box = 16.
    Now make up some similar sentences that use the number 41.
  • Tara wrote the number twenty-two like this; 202. How would you write this number? Why?
  • Jenny wrote 30 + 9 = 309. What could you do to help Jenny?
  • In one step (operation) change 49 to 9. What did you do?
  • What makes 60 and 67 different?