We use round and adjust to help us solve a problem quicker. It allows us to work with numbers that we find easier and more manageable.
We have previously used this method when adding 9 or a number with a 9 in the ones. This time we had a go at adding 8 or number with 8 in the ones.
1. Round the number to the nearest 10 and add it to the first number. (Always remembering to move from left to right on the number line when adding, because the value of our number is increasing)
2. Then adjust. Subtract the amount you added on extra to round the number to the nearest 10. Because we are subtracting when we adjust, we must jump back to the left on our number line as the value of the number is getting smaller!
Have a look at the guide to explain and model this further: