Emma and jamie used base ten block to show that 40 is one tenth of 400. whose model is nonsense?

Emma and Jammie used base ten block to show that 40 is 1/10 of 400
=> so Let say Emma and Jammie have 400 pieces cubes and they have base ten block. To know how many base ten block are there in 400, they need to separate the 400 pieces cube into ten per group.
=> 400 divided by 10
=>  400 / 10 (how many base ten blocks are there in 400)
=> 40, thus, there are 40 base ten blocks in 400 pieces of cubes.
Therefore 40 is the 1/10 of 400.