7 billion minus 5 million is 6,995,000,000
350 minus 72 is 278.
350 million
1.6 million minus 3 million is minus 1.4 million.
4,500,000
350 - 156 = 194
0.0143
3 million minus 1.2 million leaves 1.8 million.
350 million = 35,000,000,000%
350 - (20%) = 280
0.0143
3oo million alveoli