Invicta interlocking base 10 sets invicta 163959 the base 10 block set from invicta helps children to learn basic mathematical concepts including addition subtraction and place value the base ten set consists of cubes units rods tens flats hundreds and blocks thousandsthe fully interlocking system allows pupils to join the components together for easy use each piece is clearly marked in centimetre squares to highlight how each unit relates to the wholeset 52 3107 consists of 10