Hong Kong
Stage 1 - Stage 3

Reasonable Units

Lesson

What if I walked up to you right now, and offered you $1000$1000

$1000$1000 what?  I hear you say! Exactly.

You ask your friend, how far do you live from school?  They answer $20$20

$20$20 what ?  I hear you say! Exactly!

Including appropriate and reasonable units is a really important part of communication, both in mathematics and in broader society.  The units are a critical part of the information.

As we have seen in the opening statements, not including statements leaves a big hole in the mathematics and in the narrative to the story surrounding it.

Worked Example

A trader of commodities buys $6$6 tons of cocoa at $\$2.90$$2.90 per pound, and another 77 tons at \3.10$$3.10 per pound from a different source. He has a contract to sell $5$5 tons of cocoa next month at $\$2.30$$2.30 per pound, and has found a second buyer who has agreed to buy his cocoa immediately at \9.20$$9.20 per pound.

1. Assuming he has already been paid for next month's contract, solve for $n$n, the number of tons of cocoa he needs to sell to the second buyer to break even immediately.

2. How much will he make through the sale to the second buyer? Round your answer to the nearest cent.