Some people become confused when rounding as it seems to them that it does not link to their existing knowledge but to those people I say 'You're a stinky potato!' You see, we all use the skills of rounding regularly. For example, I was in a park recently and needed to put my empty marshmallow packet into the bin so...what did I do? I looked to see if there were any bins near me and I spotted three? What did I then do? Of course...I decided which was nearest and went to it. I wasn't going to waste my energy going to a bin that was not the nearest!
TdM, Creator and Star of Maths with a Mouse
When rounding to the nearest ten, we need to find the nearest tens in both directions. for example, 48 is between 40 (4 tens) and 50 (5 tens). Then, just as I did with the bins, we decide which is nearest. In this case, 50 is nearest! Simple!
The same rules apply when rounding to the nearest hundred - look both ways!
The same rules apply when rounding to the nearest one (nearest whole number).
Guess what? The same rules apply when rounding to the nearest tenth (or rounding to 1 decimal place, which is exactly the same!) For example, 2.38 is between 2.3 and 2.4 but it is nearer to 2.4
One final thing: What if it is exactly the same distance to both?
If it is a bin, it doesn't matter - choose either. If it is a number, however, let's be positive and round up!
ACTIVITY TIME
Rocket Rounding is a great activity to refine your rounding skills. Best of all, you can choose to have a number line, which is great for developing your understanding, or you can choose to have no number line. Either way....blastoff!
Nothing but net! Half Court Rounding is great (thanks, Mr Nussbaum) and you can chose how difficult you want it to be. With decimal and non-decimal options, it has rounding for everyone!
Rounding Snap is a fun game but can only be played by 2 players competing against each other on the same device. Can you be faster that your opponent to spot two numbers that round to the same whole number?
Technical Tip: To change the pace at which the numbers appear, click on the speed desired on the bar. Do not, like I did, try to slide it along - it is not a slider. Took me slightly too long to realise this! Oops!
Rounding to a certain number of decimal places or significant figures becomes easier with practice so thanks to Mathsbot, you can do just that. Unforntunately, the answers cannot be inserted online but if you are a good mathemematician, you will have a pencil and paper available.
It's time to see if you truly are an expert at rounding by rounding to unusual nearests....it is no different to rounding to the nearest hippopotamus!