Abstract: Base-ten blocks for teaching arithmetic to children, in which each block (19) has a projecting boss (27) with curved (bowed-out) sides (29) and an aperture (33) with straight sides (35), so that blocks (19) can be securely joined together to form multiples of units. Integrally made rows (37) of ten blocks each have two end bosses (41) for joining to other rows (37) to make flats (47) of one hundred units. Each flat has four bosses (51) for joining to other flats (47) to make a cube of one thousand units. The blocks have one color for units, a different color for rows of tens, a different color for flats of one hundred, and a still different color for cubes of one thousand. The blocks can be used to teach addition, multiplication, subtraction, division, etc., to children.

Abstract: Base-ten blocks for teaching arithmetic to children, in which each block (19) has a projecting boss (27) with curved (bowed-out) sides (29) and an aperture (33) with straight sides (35), so that blocks (19) can be securely joined together to form multiples of units. A row of integral blocks (37) has common wall thicknesses (42) between adjacent blocks equal to twice the thickness of the end wall (45) of the row so that the row can be correctly mated with a row of single blocks or end-to-end rows of shorter blocks. Integral rows (37) of ten blocks each have two end bosses (41) for joining to other rows (37) to make flats (47) of one hundred units. Each flat has four bosses (51) for joining to other flats (47) to make a cube of one thousand units. The blocks have one color for units, a different color for rows of tens, a different color for flats of one hundred, and a still different color for cubes of one thousand. The blocks can be used to teach addition, multiplication, subtraction, division, etc.

Abstract: Base-ten blocks for teaching arithmetic to children, in which each block (19) has a projecting boss (27) with curved (bowed-out) sides (29) and an aperture (33) with straight sides (35), so that blocks (19) can be securely joined together to form multiples of units. A row of integral blocks (37) has common wall thicknesses (42) between adjacent blocks equal to twice the thickness of the end wall (45) of the row so that the row can be correctly mated with a row of single blocks or end-to-end rows of shorter blocks. Integral rows (37) of ten blocks each have two end bosses (41) for joining to other rows (37) to make flats (47) of one hundred units. Each flat has four bosses (51) for joining to other flats (47) to make a cube of one thousand units. The blocks have one color for units, a different color for rows of tens, a different color for flats of one hundred, and a still different color for cubes of one thousand. The blocks can be used to teach addition, multiplication, subtraction, division, etc.

Abstract: Base-ten blocks for teaching arithmetic to children, in which each block (19) has a projecting boss (27) with curved (bowed-out) sides (29) and an aperture (33) with straight sides (35), so that blocks (19) can be securely joined together to form multiples of units. A row of integral blocks (37) has common wall thicknesses (42) between adjacent blocks equal to twice the thickness of the end wall (45) of the row so that the row can be correctly mated with a row of single blocks or end-to-end rows of shorter blocks. Integral rows (37) of ten blocks each have two end bosses (41) for joining to other rows (37) to make flats (47) of one hundred units. Each flat has four bosses (51) for joining to other flats (47) to make a cube of one thousand units. The blocks have one color for units, a different color for rows of tens, a different color for flats of one hundred, and a still different color for cubes of one thousand. The blocks can be used to teach addition, multiplication, subtraction, division, etc.

Abstract: A multiplication-division game containing chips (16) representing multiplication products and playing cards (14) representing multiplier-multiplicand combinations which equal the products of said chips. Each player has a placemat (10) for holding dealt and drawn cards. The chips are arranged in three piles (16) and the players take turns trying to capture the chips by combining pairs of cards whose products equal those of any one of the three top chips. The player who captures the most chips is declared winner; successful multiplier-multiplication cards being discarded. The players alternate play; with each turn a player draws a new card from a stack and matches pairs of cards against the chips until such player can no longer capture any more chips.