动词"count"指的是简单的计数，比如"count from one to ten"或"could count something on one hand"。

“calculate”描述更为复杂的计算过程，用于计算事物的数量，例如"In the maths lesson, we were asked to calculate the area of the triangle”或“We need to calculate how much profit we’ve made”。

“compute”与“calculate”相似，但更正式，常用于专业或技术性更强的场合，例句为"We need to compute how the amount of carbon in the atmosphere will affect weather patterns over the next 200 years”。

“reckon”在口语中常表示“认为”或“估计”，但在特定情况下，也用于表示“计算”，如“Could you please reckon up the bill?”。

“work out”与“calculate”意思相近，更强调计算过程和结果，常用于“we need to work out how much we’ve got left to pay our staff a bonus”或“you need to show how you worked out the answer in your maths exam”。

总结，“count”表示简单的数数，“calculate”、“compute”、“reckon”和“work out”则用于描述更为复杂的计算过程，其中“compute”更正式，“reckon”在口语中用于表示估计，“work out”强调计算的过程和结果。