Phrases with "Will you?"

[Tamara]

Hi

'But I can't reckon it; will you?'
'Eleven pounds and sixpence, is it?'

Am I right supposing that this (the form 'wil you?') is a (informal) request for action? (And 'reckon' here means 'calculate' )

Can I express the same content by the phrase: 'As I can’t <do something>, may be you will make a try to do that (instead of me)'?
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It’s impossible to learn swimming without entering the water…

[Alan]

Hi Tamara,

You asked about:

[Tamara]

Thank you, Alan, for your stab. It's quite good for the context.

(What was new for me: before I met only reckon up = calculate,
and reckon = suppose, judge, think, etc.)
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It’s impossible to learn swimming without entering the water…