This activity provides a meaningful task for practising rounding four-digit numbers to the nearest multiple of 1000. It encourages children to record their results, notice patterns and make predictions.
A possible starting point is using a number line to remind the class what is meant by rounding.
The interactive dice can be used to model the activity on an interactive whiteboard or can be used by the children as they engage with the task. You may also find that individual dice are useful.
As the task is being modelled, the results should be recorded in a table, perhaps like the one below:
|Numbers rolled||1st four-digit number||Rounds to||2nd four-digit number||Rounds to||3rd four-digit number||Rounds to||4th four-digit number||Rounds to|
|1, 2, 3 and 4||1324||1000||2314||2000||4312||4000||4123||4000|
This organisation of results will support the children to notice patterns and conjecture about when numbers will round to different multiples of 1000.
Some children may move onto the extension tasks (below).
Which numbers can we make?
What will they round to? Will they round up or down? Why?
Do they round to the same multiple of 1000? Why? When will this happen? When will it not happen?
Does it make a difference if the digits rolled are unique?
Extension 1: Did the class find examples where some of the four-digit numbers round to the same multiple of 1000? Can they then come up with a rule about when this will happen? When will two round to the same? Or three? Or four?
Extension 2: Did the class find examples where each of the four-digit numbers round to a different multiple of 1000? Why? Why not?
Extension 3: What if you change the numbers on the faces of the dice?
Extension 4: What happens if you always have 0 units and just roll three dice to generate the 10s, 100s and 1000s digits? For example, if I roll 1, 2 and 3, I can make 1230, 1320, 2130, 2310, 3120 or 3210.
Extension 5: What happens if you round to the nearest multiple of 100 instead of the nearest multiple of 1000?
Copies of the table for children to write the numbers into would be useful.
A number line would also be helpful to support children in reasoning about which whole number is closest to a given multiple of 1000.
Children may like to try Round the Three Dice which focuses on rounding to the nearest hundred.