(One must still give the regular portions of Mishloach Manos.)
The Torah writes that the Bnei Yisroel should be counted, there is a very nice Chazal in the Medrash Tenchumah.
Hashem said to Moshe, if you want to know the amount of people that form the Bnei Yisroel, take the first letters in each of the 10 tribes names.
Reuvain - Raish - 200 (thousand)
Shimon - Shin - 300 (thousand)
Yehudah - Yud - 10 (thousand)
Yissachar - Yud - 10(thousand)
Zevulan - Zayin - 7(thousand)
Binyamin - Beit - 2(thousand)
Dan - Daled - 4(thousand)
Naftali - Nun - 50(thousand)
Gad - Gimel - 3(thousand)
Asher - Alef - 1(thousand)
Yosef - Yud - 10( thousand)
We may ask, weren't the Bnei Yisroel a total of 600,000 ?
So since the counting was after the sin of the Golden Calf, and 3,000 people died by that sin, thus we are left with 597,000.
So it is as if the Pasuk is telling us, when you want to count the Bnei Yisroel, count the Rosh of the Bnei Yisroel, the first letter, and you will get 597,000.
(The Leviim were not included in the sum 600,000.)
We learn in this weeks Parsha that because of the sin of the Golden Calf, the Bnei Yisroel were commanded to give a Half a Shekel, as a Kofer Nefesh for their sin.
What is the reason for the giving of the Half a Shekel, also why does Rash tell us that Hashem showed Moshe a shekel of fire, in order for Moshe to grasp the issue of the Half a Shekel, what is the meaning of this ?
Comes Rav Elkabetz and explains that the giving of the Half a Shekel is to teach us about the way we should have Achdus in Klal Yisrael. One should not think that he could live his life and ignore the lives of ones fellow Jews. For each and every person, when he is by himself, he is only half, and he can't reach completeness unless he joins and helps his fellow Jews.
We see this idea also by Purim, Haman saw that the Jews were divided, "There is a nation, scattered abroad and dispersed amongst the nations."
He felt because of this he could destroy them.
Thus came Ester and told Mordechai, in order to survive Haman's evil decree, "Go assemble all the Jews ...".
However we must still be careful in our joining together with others, Rav Yonasan Aibeshitz brings down that we should make sure that we should only join with "Min Beh Mino", and not "Min Sheayn Beh Mino"(people that don't follow the right path.)
Therefore the Pasuk tells us that we must give Half a Shekel, that we must join with others of Klal Yisroel. Yet we must not forget the continuation of the Pasuk, it must be a joining of Shekel Hakodesh, with those that are Mino.
Comes the Minchas Yitzchak and explains what is Machzsit mean?
The word contains the following letters:
"Tzaddik" - one who is in the middle is the Tzaddik.
One who clings to the Tzaddik, is "Chet & Yud", we get Chai - Life.
However, one who tries to distance himself from the Tzaddik, he is like the dead, "Mem & Taf". The Reshayim are called dead even in their life time.
We must be careful who we cling to.
Finally, Moshe found it hard to understand how something so material, as a Half a Shekel, can be used as a form of repentance for the sin of the Golden Calf !
The Rebbe from Kotzk comes and explains that Hashem showed Moshe a Shekel of fire.
This was to hint to Moshe that everything in the world, when someone gives part of what he has to someone else, the one who gives is always loosing part of the object. This is true, except for fire, one can light as many candles as he wants from the fire, and yet he does not take away anything from the original fire.
The same is by the Half a Shekel, (Tzedakah), no matter how much one gives, he doesn't loose. For the giver in this case, is really a taker.
For the Bal - HaTurim brings down that the word "Vehnatnuh" can be read both backwards and forwards, for one who gives doesn't lack anything in the giving, for he will receive in return.
This is all true as long as he gives the charity with a fire in his heart, not that it is hard for him to give the money. But his desire is burning to give it.(The "Kotzker")
The world one lives in is constantly changing, one who is rich now, in the future he may turn out to be poor. Comes the Gra"h in Kol Eliyahu and tells us to give now, when we have the money to give. For the Trup of the word "Vehnatnuh" is "Kadmah Veh Azlah", come forward and give now, and let this righteousness of giving go before you, for one doesn't know if his own kids will need to collect from Tzedakah.
Let us keep this in mind on Purim , and apply this thought all year round.
The next time we give Tzedakah, not only should we give it with an open hand (quantity) but we should also give it with an open heart (quality).
Giving a Half a Shekel on Purim:
The Ramah (O.C. 694:1) brings down that one should give 1/2 of the present value of the value of his countries currency, in memory of the Half a Shekel that was given in Adar. Since the Pasuk writes the word Terumah three times in the Parsha, we give 3 * 1/2 of the value of the currency.
In the time of the Beis Hamikdash, the Half a Shekel was instituted as a yearly tax, this tax was placed even on the Cohanim. The tax was paid during the month of Adar (1st-15th)
Even after the destruction of the Bayit, the tax was still collected and was sent to Eretz Yisroel to support the poor Torah Scholars.
This Minhag applies till this day(and on).
The Ma Haril writes that the Half a Shekel is given on Erev Purim, before Mincha
The weight of 1/2 shekel in the times of the Chashmonaim is around 110 (grain weight).
The Sefer Piskei Teshuvos brings down the following opinions:
One who wants to do the best way in giving the Half a Shekel on Purim, he should give 3 coins that are half of the local value and each one should contain the amount of 9.6gram pure silver (the amount of the Tanach Half a Shekel's weight).(Kaf Hachaim)
If this is not available, one should then give 3 half coins of his currency, even if they do not contain silver.
If he doesn't have these half coins, he can give any 3 coins, of the currency, and have in mind to give half the currency for his requirement, and the rest for Charity.
One can also give together with a friend.
There are those that argue and say all one needs to give is one coin.(Gra"H)
The most popular Minhag nowadays, is for the Gabbai to prepare three Half a Dollars, that contain in them silver, with the weight of at least 9.ggr pure silver..
Each person comes and acquires it with his three half shekels.
When he gives the Half a Dollar he should say "Zecher Leh Machzit Ha Shekel".
According to the Biur Halacha, one should make sure that he has in mind that he is only borrowing the coins, and has in mind to give them back to allow others to be Mezakeh with them.
(Look in the Biur Halacha, why this is permitted.)
(After talking with a Coin Collecter, G.Zuckerman, I found out that the weight of the Shekel in the time of the Tanach, was about 14.4gr silver.
This means that 1gr=.2066$
Thus 1 Shekel = $3
Thus 1/2 * $1.5 = $4.00-$4.50
So we get around 15-16 Shekels equals the value of Half a Shekel of the Tanach.)
The Mishnah Berurah brings down that the Minhag is to give a Half a Shekel for every member of the family, even a fetus in the mothers stomach. Once one gives for his little son, the father is then required to give for his son every year (till his son starts giving on his own).
(Adapted from Otzar Dinim Uh Minhagim, Sefer Piske Teshuvos)
(The above should not be taken as a Psak Halcha, for final Halacha, a competent Rav should be asked. The above is written only "Kidei L'Hagdil Torah Veh Yadir")