Your little darling is much more focused now and knows a lot of concepts that were not part of his understanding a couple of months back. As he is able to now read and write, he is using this skill to explore more things. His mathematical skill is also improving and with that is coming an understanding of different units of measurement. He now has an understanding of minutes, seconds, inches, km, kg, etc. He may not be exactly sure of what the actual measurement is but the concepts have started taking shape in his mind.
What you need to know
Units of measurements are theoretical concepts which are difficult to understand unless shown practically. You can use everyday situations and things to make your child understand the different units and how each one differs from the other.