Subtraction Strip Board
Materials
- A board divided into squares (every 2 cm x 2 cm) from left to right and eleven squares from the pinnacle down. The topmost squares are numbered 1 to 18; from 1 to nine are in blue and from 10 to 18 are in red. There is a blue line that divides the board vertically after the variety nine.
- 2 units of stripes, one deck is blue with symbols 1 through nine. The different set is red, which might be subdivided into squares through blue lines. The quit rectangular of every strip is marked with the image that corresponds to the variety of its squares.
- A set of simple timber strips (now no longer colored or numbered) progressing in period from the primary and smallest strip (2cm x 2cm) through including one rectangular to its period with every succession strip in order that the remaining strip is 17 rectangular long.
Presentation
- Have the kid carry the cloth to the table.
- Show the kid the brand new board.
- Show the numbers throughout the pinnacle and the way quantity 1-nine are blue and the numbers 10-18 are in crimson.
- Tell the kid that the crimson line after the quantity nine suggests us that we can by no means have a solution larger than nine.
- Have the child install the blue stripes and crimson stripes inside the extra strip panel.
- Show the child the neat new stripes and instruct them to arrange them inside in the same way as the blue and crimson stripes on the right of the board.
- Diagram suggests entire format of the board, strips, and paper.