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{person['name']} just bought a new house. {capitalise(pronouns['their'])} new bedroom's wall and ceiling are currently painted white, but {pronouns['they']} would like to paint these {colour}.

\n

The dimensions of the floor are $\\var{length}\\,\\mathrm{m} \\times \\var{width}\\,\\mathrm{m}$ and the room is $\\var{height}\\,\\mathrm{m}$ high. 

\n

{person['name']} want{verbs} to know how much paint to buy so {pronouns['they']} can paint all four walls and the ceiling {colour}.

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The area that can be painted with one bucket of paint.

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Overestimate and therefore we round each measurement up.

", "

Underestimate and therefore we round each measurement down.

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Is it better to overestimate or underestimate in this situation?

\n

[[0]]

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Rounding each measurement to the nearest metre, estimate the whole area to be painted {colour}.

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[[0]] m2

\n

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The room is {length}m long, {width}m wide, and {height}m high.

\n

Round each measurement in the direction you decided on above. 

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Round the length to the nearest metre.

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Round the width to the nearest metre.

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Round the height to the nearest metre.

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One bucket of {colour} paint is enough to paint an area of 15m2. How many buckets should {person['name']} buy to ensure {pronouns['they']} {if(person['gender']='neutral','have','has')} enough paint?

\n

[[0]]

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Estimate the number of buckets of paint to buy, by rounding measurements of a room up to the nearest metre and estimating the total area.

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a)

\n

It is much better to have spare paint than not to have enough of it. So it is better to overestimate the area.

\n

Therefore, we round each measurement up.

\n

b)

\n

We round each of our measurements up to the nearest whole metre:

\n

Length: $\\var{length}\\,\\mathrm{m} \\approx \\var{l}\\,\\mathrm{m}$.

\n

Width: $\\var{width}\\,\\mathrm{m} \\approx \\var{w}\\,\\mathrm{m}$.

\n

Height: $\\var{height}\\,\\mathrm{m} \\approx \\var{h}\\,\\mathrm{m}$.

\n

The total area consists of five areas: two walls of $\\var{l}\\,\\text{m} \\times \\var{h}\\,\\text{m}$ (length by height); two walls of $\\var{w}\\,\\text{m} \\times \\var{h}\\,\\text{m}$ (width by height); and a ceiling of $\\var{l}\\,\\text{m} \\times \\var{w}\\,\\text{m}$ (length by width).

\n

\\[ \\begin{align}
\\var{l}\\,\\text{m} \\times \\var{h}\\,\\text{m} &= \\var{l*h}\\,\\text{m}^2
\\\\ \\var{w}\\,\\text{m} \\times \\var{h}\\,\\text{m} &= \\var{w*h}\\,\\text{m}^2
\\\\ \\var{l}\\,\\text{m} \\times \\var{w}\\,\\text{m} &= \\var{l*w}\\,\\text{m}^2
\\end{align}\\]

\n

Therefore, the total area {person['name']} needs to paint is

\n

\\[ \\var{2*l*h} + \\var{2*w*h} + \\var{l*w} \\,\\mathrm{m}^2 = \\var{rall}\\,\\mathrm{m}^2 \\text{.} \\]

\n

c)

\n

The exact number of buckets needed is

\n

\\[\\var{rall}\\,\\text{m}^2 \\div 15\\,\\text{m}^2 = \\var{rall/15} \\text{.}\\]

\n

{person['name']} can only buy a whole number of buckets, so {pronouns['they']} need{verbs} to decide between {buckets-1} and {buckets} paint buckets. As it is better to buy more paint than not buy enough, {pronouns['they']} should buy {buckets} buckets of {colour} paint.

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