Mathematics workshop
Measuring and comparing
Equal units, rulers, time and money in clear diagrams.
Theory
Measure with equal units
Place equal units end to end from the ribbon’s start to its end. Leave no gaps or overlaps. A larger unit gives a smaller count for the same length. These are model units, not physical screen centimetres.
Measure the ribbon with equal units.
A ruler: start, end and units
Neighbouring marks on this model ruler are 1 cm apart. Length counts the gaps, not the marks. Align zero with the ribbon’s start, or subtract the two endpoint readings. 10 cm = 1 dm. The drawing scales and is not a physical ruler.
Measure the ribbon’s length in cm.
At the ribbon’s ends: 2 cm · 7 cm.
Hours and minutes
The long hand shows minutes: each number-to-number interval is 5 minutes. The short hand shows hours and gradually moves towards the next hour. At 3:30 the long hand points to 6 and the short hand is halfway between 3 and 4. One hour is 60 minutes.
Set the clock to 3:30.
Payment and change
Count coin values rather than the number of coins. For example, 5 ₽ and 2 ₽ make 7 ₽. Different coins can make the same amount. Exact payment matches the price. When someone pays more, the price plus their change must equal the amount paid.
A notebook costs 7 ₽. Build the exact payment.
Selected total:
Choose a coin group to remove one coin.
Practice
Try different ways. Undo a step or start again when you need to.
Choose an activity
To 10 cm · hours and half hours · prices to 15 ₽
Measure the ribbon with equal units.
Games
Build your answer and choose Check. Ask for a hint if you need one.
Choose an activity
To 10 cm · hours and half hours · prices to 15 ₽
Measure the ribbon with equal units.