Task 10. The child was given one base-ten long and four units. The interviewer had a collection of units before him.
The child was asked, "Lend me six little blocks from what you have now." If the child observed that there were 14 units but nit enough loose units to do this, an offer was made to trad some of the interviewer's units for the child's long. When a trade was suggested by the child, it was made. The child was then asked if that was a fair trade.
The purpose of this task was to see if the child would trade the long for (1) 10 units or (2) only enough units to be able to give away the 6 asked for.
All children saw that the combination of 1 long and 4 units was the same as 14 units and that they needed more units to be able to give away 6 of them.