what does "allow for the waste" mean?

[Katerina]

English Language Tests, Intermediate level

ESL/EFL Test #421 "English Slang Idioms (161)", question 10

"When figuring our what materials you will need to complete the job, don't forget to ......... for waste," the contractor told Jim.

(a) allow
(b) make
(c) a lot
(d) reduce

English Language Tests, Intermediate level

ESL/EFL Test #421 "English Slang Idioms (161)", answer 10

"When figuring our what materials you will need to complete the job, don't forget to allow for waste," the contractor told Jim.

Correct answer: (a) allow

Your answer was: incorrect
"When figuring our what materials you will need to complete the job, don't forget to reduce for waste," the contractor told Jim.
_________________________

what does allow for the waste mean?

Katerina

[Yankee]

Hi Katerina

'Allow for' basically means to plan for or make provisions for something. When a product is manufactured, it is not uncommon that a little bit of the raw material needed is not actually used in the final product. For example, there might be some bits and pieces of raw material left over, and if these bits and pieces cannot be used in another product, then they are 'waste'. Therefore, if you "allow for waste" when ordering material, you order more material than will actually be used in the final product.
See definition 9 here.
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I'm not sure why the expression "allow for" (or "allow for waste") was categorized as a "slang idiom", however. To me the usage is standard, not slang.
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Hi Torsten
This test sentence contains a typo. The word 'our' should be changed to 'out':
"When figuring out what materials you will need to complete the job, ... "
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