1. Nomography is a useful technique for engineers to solve complex mathematical problems without using extensive calculations.
（词义：图解方法对工程师来说是一个有用的技术，可以解决复杂的数学问题，而无需进行复杂的计算。）

2. By using nomography, the scientist was able to quickly estimate the size of the population based on a few key variables.
（词义：科学家利用图解法，根据几个关键变量，能够快速估计人口规模。）