Estimate the order of magnitude of the length, in

meters, of each of the following: (a) a mouse, (b) a

pool cue, (c) a basketball court, (d) an elephant, (e) a

city block.

A) a mouse, to an order of magnitude = 0.1 m (a tenth of a meter) That would be a big mouse but the alternatives are 1 meter or one hundredth of a meter ... so go with 1/10th

b) Easy = 1 meter

c) two choices 10m or 100 m. Go with 100 m

d) Stretch it out, trunk tip to tail tip - call it 10 m

e) Your choice 100 m or 1000 m ... These are estimates. So long as you are within one order of magnitude you can't really be given wrong. So I'd say 100m