How many people died in the nazi concentration camps and death trains and marches?

The United States Holocaust Memorial Museum has a page titled, Documenting Numbers of Victims of the Holocaust and Nazi Persecution which contains some good estimates, and also details that may help explain why it is do difficult to obtain good estimates for the number of people murdered by the Nazis.

Why is it hard to estimate the number of people murdered?

As the page Documenting Numbers of Victims of the Holocaust and Nazi Persecution cited above observes:

Calculating the numbers of individuals who were killed as the result of Nazi policies is a difficult task. There is no single wartime document created by Nazi officials that spells out how many people were killed in the Holocaust or World War II.

To accurately estimate the extent of human losses, scholars, Jewish organizations, and governmental agencies since the 1940s have relied on a variety of different records, such as census reports, captured German and Axis archives, and postwar investigations, to compile these statistics. As more documents come to light or as scholars arrive at a more precise understanding of the Holocaust, estimates of human losses may change.

The single most important thing to keep in mind when attempting to document numbers of victims of the Holocaust is that no one master list of those who perished exists anywhere in the world.

They also note the main reasons why there is no single document listing the numbers of victims:

1. Compilation of comprehensive statistics of Jews killed by German and other Axis authorities began in 1942 and 1943. It broke down during the last year and a half of the war.

2. Beginning in 1943, as it became clear that they would lose the war, the Germans and their Axis partners destroyed much of the existing documentation. They also destroyed physical evidence of mass murder.

3. No personnel were available or inclined to count Jewish deaths until the very end of World War II and the Nazi regime. Hence, total estimates are calculated only after the end of the war and are based on demographic loss data and the documents of the perpetrators. Though fragmentary, these sources provide essential figures from which to make calculations.

Numbers of people killed by the Nazis

The current best estimates for the number of people murdered are:

• Jews: 6 million
• Soviet civilians: around 7 million (including 1.3 Soviet Jewish civilians, who are included in the 6 million figure for Jews)
• Soviet prisoners of war: around 3 million (including about 50,000 Jewish soldiers)
• Non-Jewish Polish civilians: around 1.8 million (including between 50,000 and 100,000 members of the Polish elites)
• Serb civilians (on the territory of Croatia, Bosnia and Herzegovina): 312,000
• People with disabilities living in institutions: up to 250,000
• Roma (Gypsies): 196,000–220,000
• Jehovah's Witnesses: around 1,900
• Repeat criminal offenders and so-called asocials: at least 70,000
• German political opponents and resistance activists in Axis-occupied territory: undetermined
• Homosexuals: hundreds, possibly thousands (possibly also counted in part under the 70,000 repeat criminal offenders and so-called asocials noted above)

(source - United States Holocaust Memorial Museum)

Which suggests that in all, something like 18 million people were murdered by the Nazis (bearing in mind the caveats noted above).

The Documenting Numbers of Victims of the Holocaust and Nazi Persecution page cited above also has a table showing a breakdown of best estimates for the breakdown of Jewish losses according to location of death.

A couple of other sites that might be of interest to your daughter are:

• Documenting the Holocaust from the London Grid for Learning, which includes discussion about some of the resources available to researchers at the Wiener Library.

• The Documents page from A Teacher's Guide to the Holocaust by the Florida Center for Instructional Technology.