Lesson · Grade 3 · Mathematics
Units of Time: From Seconds to Years
- Grade 3
- Mathematics
- 59 s
- British Columbia
- BC3-MA-26
A table builds up step by step to show how many of each small unit of time make the next bigger one: 60 seconds, 60 minutes, 24 hours, 7 days and 12 months. Then the fact that 7 days make 1 week answers "How many days are in 3 weeks?" by adding 7 + 7 + 7 = 21 and counting 21 day squares to check.
Anyone can watch two lessons on the website without an account. Signing in is free, no payment and no card, and opens three a day; Plus has no limit.
Loading
In one sentence
The question this lesson answers
How many days are in 3 weeks?
To find out, let us see how units of time fit together.
Transcript
What the lesson says
How many days are in 3 weeks?
To find out, let us see how units of time fit together.
60 seconds make 1 minute.
60 minutes make 1 hour.
24 hours make 1 day.
7 days make 1 week.
12 months make 1 year.
For our question, we need this fact: 7 days make 1 week.
Week 1 has 7 days.
Week 2 and week 3 have 7 days each.
Add them up: 7 plus 7 plus 7 is 21.
Count the days to check: there are 21.
So 3 weeks is 21 days.
Small units of time add up to make the big ones.
Curriculum
Where this fits
- British Columbia, Grade 3
Mathematics, Geometry and measurement: time conceptsBC3-MA-26
Previous: Area: How Many Squares Cover a ShapeNext: 3D Objects: Faces, Edges and Vertices
The outcomes and strands follow the British Columbia curriculum.
Keep going
1 min 12 s3:15 p.m. or 15:15? Morning, afternoon and the 24-hour clock
Grade 4 · 1 min 12 s
1 min 26 s3D Objects: Faces, Edges and Vertices
Grade 3 · 1 min 26 s
1 min 21 sArea and Perimeter: What Is the Difference?
Grade 5 · 1 min 21 s
1 min 5 sArea of a Circle from the Radius or the Diameter
Grade 7 · 1 min 5 s
1 min 14 sArea of a Parallelogram: Cut and Slide into a Rectangle
Grade 6 · 1 min 14 s
1 min 18 sArea of a Rectangle: Count the Squares, Then Multiply
Grade 5 · 1 min 18 s
1 min 16 sArea of a Trapezoid: Two Copies Make a Parallelogram
Grade 6 · 1 min 16 s
1 min 19 sArea of a Triangle: Half of a Parallelogram
Grade 6 · 1 min 19 s
- All Grade 3 Mathematics lessons
- Teachers: the maths worksheets for Grade 3 are in the dashboard, each with a worked example and a proven answer key.
- Try the graph paper, free for everyone, no account needed.
- Create a free account to watch three lessons a day, no payment and no card.