Mathematics · Year 3

Measurement: Length, Perimeter, and Time

🔢 MathematicsMedium14 min
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you are a den! 🏕️ You need to know how each of is, how far around the , and what your are . All of those are and you are to all of them! We will , , and by .

us how or is. We use in : (m) for big things like , (cm) for like , and (mm) for things like the of a . of a as one big , a as the of your , and a as the of a .

ConversionExample
1 m = 100 cmA door is about 2 m = 200 cm tall
1 cm = 10 mmA crayon is about 8 cm = 80 mm long
1 m = 1000 mmA guitar is about 1 m = 1000 mm long
Converting between length units

: the 100 (like 100 in a ), so there are 100 in 1 . The 1000, so there are 1000 in 1 . 💡

✍️ Fill in the missing numbers to complete these conversions.

3 m = cm, and 5 cm = mm.

Now let us about . The of a is the all the way around its like a around a . To it, you add up the of all the . If a has of 5 cm, 3 cm, 5 cm, and 3 cm, the is 5 + 3 + 5 + 3 = 16 cm. you have every !

Rectangle ABCD: sides AB = 5 cm, BC = 3 cm, CD = 5 cm, DA = 3 cm. Perimeter = 5+3+5+3 = 16 cm.

🔗 Match each shape description to its correct perimeter. Add all the sides carefully! 📐

  • Square with sides of 5 cm

  • Rectangle: 6 cm and 2 cm sides

  • Triangle: sides 3 cm, 4 cm, 5 cm

  • Rectangle: 7 cm and 4 cm sides

A has all the . For a you can one by the of of them all. A with 4 cm : 4 × 4 = 16 cm. ! ⭐

to at ! ⏰ An (the with ) has 12 around the . The to the and the to the . Each gap is 5 , but you can for . as by a , like 09:47, 9 and 47 .

This clock shows 9:47 — the short hand is nearly at 10 (9 hours) and the long hand is at the 9 then 2 more marks (47 minutes).

To on an : which big the has , it by 5, then on the . For , the 9 (= 45 ) and 2 more = 47 . ✅

🗂️ Sort these times into AM (morning, midnight to midday) or PM (afternoon and evening, midday to midnight). 🌅🌙

  • 07:30 — breakfast time

  • 14:15 — after school

  • 11:55 — nearly lunch

  • 20:00 — bedtime

  • 08:05 — school starts

  • 17:30 — teatime

doneyou have , , , and the ! 🎉 : , , and us ; add all to ; and use the or on a to the to the . Now with the !

Quiz time! 📝

Length, Perimeter, and Time Quiz

Question 1 of 5

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How many are in 2 ?

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