Modern Indians have lost all contact with their own texts.
Rather they read history written by Europeans who got their math from the Arabs, who got it from Hindus; and they regard this 3rd-hand knowledge of Europeans as true and repeat it ignorantly.
Both zero and negative numbers were conceptually so difficult for the Arabs and the Europeans that they took centuries to understand it.
This is because these arise from Hindu philosophical ideas as @MeruPrastara's book shows.
Algebra (Bijaganita) came from India and was described by Al-Khwarizmi based on translations from Sanskrit. European historians then called him the "inventor of Algebra."
Yes, Western myth-making assigned knowledge to Babylonians or Greek. Because middle-east or Greece was kosher for Abrahamic and White European origins. History is steeped in White racism and Church fabrications.
In the "golden age" of Arab Science they had a massive translation movement. They paid translators the weight of the Sanskrit manuscript in gold to translate it to Arabic. For mother tongue understanding. What does GOI do? #narendramodi
When Arabs copied Indian math and astronomy they retained this meridian.
When Europeans copies Indian math and astronomy from the Arabs this was ultimately erased.
The Arabs had great difficulty understanding negative numbers. So they read about the negative numbers but couldn't understand them initially. This is why Al Khwarizmi, copied Algebra but also missed out on this.