21) k stands for kilo, and means 1000. 150 kL = 150,000 L

22) This threw me ! d stands for 1/10, but it’s (almost) NEVER used. There are 10 decimetres in a metre, but that’s about it.

So 38 dkm = 1/10 of 38 km = 1/10 of 38,000 m = 3,800 m

23) Well ! We’re talking grams and decigrams, but hg ? That’s a new one for me…

24) 1cm cubed (or 1 c.c. on a syringe) = 1 mL

25) m stands for milli and means 1/1000. 0.036s = 36ms

26) c stands for centi, means 1/100. Combine that with milli, and you find 10 mm = 1cm. So 0.67cm = 6.7mm

—- Edit —-

Oh! The second link is a help. dg is a decigram, or 1/10 of a gram. hg is hectogram, or 100 grams.

So 5.4hg = 540g = 5,400dg.

In real life, you’d call it 0.54kg, or about a pound on the old scale.

3.8m

.0054dg or 5.4 x 10 to the power of -3

1mL

.000036 or 3.6 x 10 to the power of -5

.067mm

good luck