Problem Slips: Subtraction Working Charts
Made by Nienhuis Montessori · shipped by Heutink International (Netherlands) About the maker
Two sets of colour coded slips carrying the unit subtraction equations, one set for each of the two subtraction working charts, each in its own plastic box. A child working the charts needs a supply of problems, and a slip drawn at random is a different thing from a page worked top to bottom: there is no order to lean on, so each combination has to be known rather than remembered from its neighbour. Working charts sold separately. Acrylic and cardstock, for ages 3 to 12.
“The greatest sign of success for a teacher is to be able to say, 'The children are now working as if I did not exist.'”
The Problem Slips for Subtraction Working Charts serve as a bridge between concrete mathematical manipulation and abstract numerical thinking in the Montessori mathematics curriculum.
- Masters subtraction facts from 18-1 through systematic practice
- Develops pattern recognition in subtraction relationships
- Builds speed and accuracy in mental calculation
- Strengthens abstract mathematical thinking through repeated exposure
Read More
These cards, stored in clear acrylic boxes for easy visibility and access, present subtraction problems in a systematic sequence that respects the child's mathematical development. The green line indicators on each slip provide visual guidance without overwhelming the learner, allowing children to work through subtraction facts at their own pace. Unlike traditional worksheets, these problem slips isolate individual equations, enabling focused concentration on one mathematical relationship at a time. The cards complement the Subtraction Working Charts by providing structured practice opportunities that reinforce pattern recognition in subtraction facts. Through repeated work with these problem slips, children internalize the relationships between numbers, building the foundation for mental calculation. The clear acrylic storage boxes ensure the materials remain organized and accessible, inviting independent mathematical exploration.

How to present it
Follow the Montessori method of presentation for optimal child development.
Place the two acrylic boxes containing problem slips on a table mat. Have the Subtraction Working Chart and corresponding answer tiles ready nearby. Ensure the workspace is organized with a small container for completed slips.
- 1
Select the first problem slip from the box, noting the green line indicator
Start with larger minuends (18, 17) as these are typically introduced first - 2
Read the subtraction problem aloud, then solve using the working chart if needed
Encourage finger tracing along the chart lines to find answers - 3
Record or place the answer using tiles or writing materials
Some children benefit from saying the complete equation aloud - 4
Check the answer using the control chart before moving to the next slip
Self-correction builds confidence and independence - 5
Continue through the sequence, placing completed slips in the designated container
Work for 15-20 minutes or until natural interest wanes
Every Child Is a Little Creator

Heritage
Since 1929

In classrooms
Around the world

European brands
Nienhuis, GAM, Educo

AMI approved
To the association standard

Problem Slips: Subtraction Working Charts
