Engineering 'aha' Moments in Number
Calculating Changes is professional learning network grounded in the classroom. Teachers supporting teachers to build a firmly founded, creative number sense through Infant years, then extending it across the primary years. The network has built a rich resource of ideas, activities and approaches, accessible through this site, within the context of all children learning to work like a mathematician in best practice classrooms.

Have you seen Working Mathematically with Infants?


Free Tour

... In Brief

... Materials

... Activities

... Membership

... PD Programs

... Stories

... Snapshots

... Background

... Evaluations


... Content Finder

... Year Level Finder

... Activities List



... Activities

... Support

All the ingredients.

Poly Plug, calculators, kids & a reason for mathematical conversation.


Working Mathematically with Infants

We are very happy with our WMI kit. We are problem solving and polyplugging away and having a great time. ... Kerry Lee, Buninyong Primary School

Read more testimony in the Stories link.

  • Only available to Members of Calculating Changes (see above)
  • 45 Threaded Activities and 48 Investigations for Years K - 2
  • 10 weeks of number work detailed in 6 scope and sequence planners
    - one planner per semester in each year
  • Planners are flexible - you map the weeks into your yearly program
  • Weeks build on weeks, years build on years
  • Planners are designed to support group work/ work stations/ learning centres and whole class investigations
  • Each kit contains:
    • 25 Poly Plug
    • Manual with weekly planners
  • Integrates with Maths With Attitude in Year 3 and beyond to continue a curriculum centred on learning to work like a mathematician

Read about the great learning with WMI at Boroondara Park Primary School.


WMI Manual Part A
for further background
Sample Planner

Ordering Details

$330 per kit (members only)
$330 membership with kit
  • Use our Order Form
    or send your school purchase order to:
    or contact us.
  • Already a member and purchased at least 20 Poly Plug in the past?
    ...Order the manual ($55) separately AND extra Poly Plug at the special rate.
  • Outside Australia?
    ...Please contact us for a quote.
1. Calculating Changes membership is a once only fee.
2. Please include an email address on the order.
3. Prices do not include freight.
Professional Development

WMI has been constructed to support in-house professional development. We are also available to provide programs stimulating the use of Calculating Changes through your school:

  • 2 hours
  • 1 day
  • 6 days
See PD Progams and contact Doug. Williams.

Members can also order

  • additional Poly Plug for $11 (normally $1350)

  • additional manuals for $2750 (normally $55)

  • Picture Puzzles for $110 (normally $165)

Calculating Changes ... is a division of ... Mathematics Centre