It's about one-one-hundred-fiftieth as heavy as an Octopus
In other words, the weight of an Octopus is 160 times 0.000000000310 megatonnes.(for Giant Pacific Octopus, Enteroctopus) (Adult, average)
The adult North Pacific Giant Octopus usually weighs around 0.0000000500 megatonnes. It is the largest octopus species and is known for its considerable intelligence, including the ability to open jars, solve mazes, and mimic other octopuses.
It's about 150 times as heavy as a Playing Card
In other words, the weight of a Playing Card is 0.0059 times 0.000000000310 megatonnes.(ISO 216 B8 size, 2.5" x 3.5")
A single ISO 216 B8-size playing card weighs 0.00000000000180 megatonnes. Although this size is the most common home playing card, many casinos use "bridge size" cards — 2,640 sq. mm (4.036 sq. in) smaller in area.
It's about 200 times as heavy as a Paper Clip
In other words, 0.000000000310 megatonnes is 220 times the weight of a Paper Clip, and the weight of a Paper Clip is 0.0045 times that amount.(average)
Notwithstanding the tremendous variation in sizes and materials, a typical paperclip weighs about 0.00000000000140 megatonnes. The country of Norway has used the paper clip as something of a national symbol since the end of World War II based on the erroneous notion that the paperclip was invented by a Norwegian, Johan Vaaler. However, the paperclip had already been in existence for at least 30 years by the time of Vaaler patented his paperclip design.
It's about one-two-hundred-fiftieth as heavy as a Beer Keg
In other words, 0.000000000310 megatonnes is 0.004258 times the weight of a Beer Keg, and the weight of a Beer Keg is 234.90 times that amount.(for US half-barrel, full keg; draft beer; including keg itself, stainless steel)
A typical, half-barrel beer keg weighs 0.00000007280 megatonnes when full. A keg of this size contains 15.5 gallons of beer, or the equivalent of 6.8 cases.
It's about one-three-hundredth as heavy as a Kangaroo
In other words, 0.000000000310 megatonnes is 0.0036 times the weight of a Kangaroo, and the weight of a Kangaroo is 280 times that amount.(for red kangaroo, Macropus rufus) (adult, male)
An adult, male red kangaroo weighs up to 0.0000000850 megatonnes. Fantastic jumpers, red kangaroos can leap horizontally 9 m (30 ft) and vertically 3 m (9 ft) in a single bound.
It's about 300 times as heavy as a Jelly Bean
In other words, 0.000000000310 megatonnes is 280 times the weight of a Jelly Bean, and the weight of a Jelly Bean is 0.0036 times that amount.(for Jelly Belly beans; approximate)
Made of sugar, corn syrup, and pectin, a single jelly bean weighs about 0.00000000000110 megatonnes. President Ronald Reagan cited jelly beans as his favorite candy and 0.00000320 megatonnes of the candies were served at his first inauguration in 1981.
It's about 400 times as heavy as a Nail
In other words, 0.000000000310 megatonnes is 390 times the weight of a Nail, and the weight of a Nail is 0.0026 times that amount.(for 15-gauge, 2-inch, finishing nails)
A two-inch finishing nail weighs 0.000000000000790 megatonnes. Nails have been in use for more than 5,400 years and were ven used as a medium of exchange in ancient times.