Description

The Subtraction Strip Board with Strips & Tray is a foundational Montessori Mathematics material used to explore subtraction facts from $18 - 9$ down to $1 - 1$. By placing calibrated hardwood strips across a numbered grid board, children visually and physically experience subtraction as the process of taking away, finding the difference, or discovering complementary number pairs.Key Benefits & Learning OutcomesConcrete Subtraction Perception: Transforms abstract mental subtraction into a tangible visual measurement by using strips to cover up or isolate quantities on a number line.Exploration of Inverse Operations: Reinforces the direct relationship between addition and subtraction by utilizing the same length proportions found on the Addition Strip Board.Self-Correction & Error Control: Printed grid numbers allow children to immediately read the remaining answer at the edge of the strip, enabling independent self-verification without adult intervention.Preparation for Abstract Math: Works in tandem with subtraction control charts and record booklets, helping children internalize basic math facts through physical repetition before transitioning to mental math.Design & MaterialsIncluded Components:1 Wooden Subtraction Grid Board: Features a grid 18 squares wide, with numbers 1 through 18 printed horizontally across the top margin (1–9 in hardwood tones/blue and 10–18 in red, divided by a vertical line after 10).1 Wooden Storage Tray: Houses three distinct sets of hardwood strips:17 Natural Wooden Strips (Unnumbered/Plain): Used to cover up numbers on the right side of the board that are not part of the starting minuend.9 Blue Strips (Numbered 1–9): Represent the minuend or positive quantities, printed with blue numerals at the end.9 Red Strips (Numbered 1–9): Represent the subtrahend (the amount being subtracted), marked with calibrated square segment lines and red numerals.Material: Solid natural hardwood finished with smooth, non-toxic painted colors and clear grid lines.Features: Precision-milled strip dimensions designed for exact square-for-square alignment on the grid board, built for continuous tabletop practice in classroom and home environments.