Sure! Let's fill in the blanks for the given question about prefixes in the metric system.
a) For ten times the base unit: In the metric system, the prefix used to indicate ten times the base unit is 'deca-'. The prefix 'deca-' is used to denote a factor of 10. For example, one decameter (dam) is equal to 10 meters.
b) For one tenth of the base unit: In the metric system, the prefix used to indicate one tenth of the base unit is 'deci-'. The prefix 'deci-' is used to denote a factor of 0.1 (or 1/10). For example, one decimeter (dm) is equal to 0.1 meters.
So the completed questions are:
a) ten times the base unit is 'deca-'
b) one tenth of the base unit is 'deci-'
