Measurement is the most "real-life" math you can do with a six-year-old. Every grocery trip, every bedtime, every coin in a piggy bank is a tiny measurement lesson. The trick is just to notice them.
What first grade aims for
By the end of first grade, a child typically can:
compare two objects' lengths and tell which is longer or shorter,
measure short objects with a ruler in centimetres,
read whole hours and half hours on an analog clock,
recognise the most common coins and add up small amounts.
Different countries set the bar slightly differently. In the US the focus is more on inches and a richer money skill set; in Slovakia and Germany cents and centimetres dominate. The thinking is the same.
Length at home
Measure your child's height once a month — they will love it.
Make a tape from string, mark a centimetre with a pen and "ruler" the toys.
Compare two pencils, two crayons, two flowers in the garden — always asking which is longer.
Time at home
Get an old analog clock if you only have digital ones at home — kids learn to read clocks faster when they can touch the hands.
Talk in clock language: "we leave at 8 o'clock", "story time is at half past 7".
Make a paper plate clock together — drawn hands, a hole through the centre, a paper-fastener pivot.
Money at home
Empty a piggy bank and sort coins by value.
Play "shop": put price tags on three toys, give the child some coins, let them buy.
At the bakery, ask "do we have enough? how much more do we need?" and let them try to figure it out.
Common pitfalls
Measuring with crooked hand-spans. Make sure the child holds the hand fully open every time, or the answer will be different.
Reading 4:30 as "4:6". Some kids read the position of the minute hand as the number it points to. Remind them: the minute hand counts in fives.
Confusing big coins with small ones. A 5-cent coin is sometimes physically bigger than a 10-cent coin. Always read the number.
Don't worry about precision
A first-grader's "10 cm" might be 7 cm or 13 cm. That is fine. The goal is that they understand the idea of measuring — that you put a unit next to an object and count. Precision comes later.