It's about 7,500,000,000 times as big as a King Size Bed.
In other words, 31,000,000 dunams is 7,690,000,000 times the size of a King Size Bed, and the size of a King Size Bed is 0.000000000130 times that amount.(North American/Australian standard; length; mattress only)
A King-Size mattress measures 0.00403 dunams in total area. Although most antique beds were smaller than modern beds, it was not uncommon for beds in the medieval Europe to reach 0.005 dunams for those in positions of wealth or power.
It's about 30,000,000,000 times as big as a Bath Towel.
In other words, 31,000,000 dunams is 28,603,000,000 times the size of a Bath Towel, and the size of a Bath Towel is 0.0000000000349610 times that amount.(for Fieldcrest Luxury Solid Towels)
Bath towels typically measure 142.24 cm (56 in) by 76.2 cm (30 in), for a total area of about 0.0010838 dunams. The city of Bursa, Turkey is known as the birthplace of the modern towel.
It's about 300,000,000,000 times as big as an Airplane Tray Table.
In other words, 31,000,000 dunams is 307,000,000,000 times the size of an Airplane Tray Table, and the size of an Airplane Tray Table is 0.000000000003260 times that amount.(average)
With wide variation among different models of airplanes, in-flight tray tables measure around 41.2 cm (16.5 in) x 24.1 cm (9.5 in) for a total area of 0.000101 dunams. Flight safety rules require that the tray tables be upright and locked during takeoff and landing so as to reduce the risk of passenger abdominal injury.
It's about 750,000,000,000 times as big as an Apple iPad.
In other words, 31,000,000 dunams is 774,600,000,000 times the size of an Apple iPad, and the size of an Apple iPad is 0.0000000000012910 times that amount.(for 9.7 inch, Apple iPad Air MD785LL/B)
An Apple iPad measures 23 cm (9.4 in) x 17 cm (6.6 in) for a total device area of 0.000040020 dunams. The base model iPad Air features 16 GB of storage capacity.
It's about 5,500,000,000,000 times as big as a Playing Card.
In other words, the size of a Playing Card is 0.000000000000180 times 31,000,000 dunams.(ISO 216 B8 size)
A single ISO 216 B8-size playing card measures 0.00000560 dunams. Although this size is the most common playing card, many casinos use the smaller "bridge size" card — 0.00000260 dunams smaller.
It's about 5,500,000,000,000 times as big as a Post-it® Note (3M).
In other words, the size of a Post-it® Note (3M) is 0.000000000000180 times 31,000,000 dunams.(3M) (generically sticky notes, a.k.a. repositionable notes, a.k.a. repositional notes)
A Post-it® Note measures 0.00000540 dunams in total area. In September, 1989, Hurricane Hugo swept through Charleston, South Carolina with winds up to 230 kph (140 mph), uprooting eight oak trees in Mr. Bruce Brakefield's yard, but leaving in place a Post-it® note attached to his front door.
It's about 40,000,000,000,000 times as big as a Secure Digital (SD) card.
In other words, the size of a Secure Digital (SD) card is 0.0000000000000250 times 31,000,000 dunams.A Secure Digital (SD) card measures 3.2 cm by 2.4 cm for a total area of 0.000000770 dunams. SDXC Cards, the latest standard for the technology, will allow the cards to hold up to 2 terabytes of data.