What does “up by 500” mean?

Question

Source (news article): Russia to Start Bombing in Syria ASAP

Example:

Russia has also sent 16 helicopters, two surface-to-air missile batteries, nine T-90 tanks, and enough modular housing to hold 2,000 Russian troops, up by 500 in just a matter of hours. U.S. officials believe there are at least 500 Russian troops on the ground now, presumably to serve as advisers to Syrian forces on the front lines and help them launch more precise artillery strikes and support their ground forces from the air.

I'm not really sure that I am following that particular sentence. The line up by 500 throws me off completely. What exactly does it say? And break it down for me in terms of grammar too, please.

Answer 1

It seems that 500 refers to the number of Russian troops. Said that, earlier, they had modular housing to occupy 1500 troops. But in just a matter of hours, Russia sent housing having more capacity. Of course, along with all other arms mentioned.

Answer 2

INCREASE

in·crease.

verb

1.become or make greater in size, amount, intensity, or degree: "gun use is increasing at an alarming rate" ·

synonyms: (A through T removed) ... up · jack up · hike up · bump up · torque up · crank up ... (V through Z removed)

Example:

...and enough modular housing to hold 2,000 Russian troops, up by 500 in just a matter of hours.

Where there was enough housing for 1500 troops, in a matter of hours, there is now housing for 2000. The amount of modular housing available to Russian troops increased by 500 in a matter of hours - i.e. it was flown into the country and assembled with intent.

Answer 3

Longman Dce lists 23 uses of the preposition by. No. 10 refers to change/difference: by can be used to say how great a change or difference is:

• The temperature fell by 15 degrees from 20 to 5 in one hour.

• Sales have risen by 10 per cent.

• The water level is up by three feet. (is up means the same as has risen)

http://www.ldoceonline.com/dictionary/by_1

Answer 4

The use of the phrase 'up by' or 'down by' followed by a quantifier signifies that the subject in hand has increased, or decreased by a specified amount.

In this particular case the phrase is stating that the last subject has increased in quantity by 500, meaning the amount of Russian Troops has increased from 2,000 by 500.