# Math Challenge 2019

Discussion in 'Mathematics' started by Shin0bi3Z, Jul 2, 2019.

1. ### Shin0bi3ZNew commenter

OK, I think doing that helps to see the whole number that you will end up with a lot faster.

2. ### sammiloczyNew commenter

27+48, I'd borrow 2 from 27 and place on the 48 to make the calculation 25+50

minstrel likes this.

I assume the post refers to what processes are being done for the calculation.

You are confusing efficiency with a particular algorithm.

Efficiency is something like take 3 from the 48 and add it to the 27 to give 30 + 45 which has an eviqualent total to the original calculation.

Whilst notionally you might think want to say that there is only one calculation, this is not what you are actually doing.

For example.
This ignores the process of increasing 48 to 50 and registering the difference is 2. Which is then used in the second step.

You choice is the addition by column algorithm. Or a form of chunking where you add to make one or both of the values 'round' (multiples of 10) and then correct.

In terms of efficience the measure of the efficiency changes upon how many addends one needs to add up.

In terms of mental speed I find the chunking quicker and somewhat automatic.

Why not 20 + 40 = 60, 8+7 =15, 60 +15 =75? If you going to separate the units and the tens that is?