Preview · the opening missionRead this to the class:
Two cousins, Ana and Theo, each got "half a granola bar" from their grandpa. Theo looked at Ana's piece and said, "That's not fair! Your half is bigger than mine!" Grandpa said, "A half is a half. They must be the same." Ana's half came from a big bar and Theo's from a small one. Your team's job: find out whether half is always the same size, and teach Grandpa what a fair share really is.
Teams of three, with jobs that rotate after each bar: Folder (folds and creases the bar), Measurer (checks every part with the ruler), Recorder (labels the parts and fills in the table).
Look inside the PDF
Sample pages, stamped “preview”. The download is the clean, full lesson.
In the full lesson PDF
7 printable pages
- Predict (5–10 min)
- Hunt (20 min)
- Reveal (10–15 min)
- Act (10 min)
- Background for the teacher
- Assessment
- Student sheet
- Worksheet: Label it
- Worksheet: Try it at home
On the student sheet
- My prediction
- Our bars
- What did we find?
- My note to Grandpa
- Exit ticket
- Label it
- Try it at home
US Letter, prints cleanly in black and white. The student sheet is on its own page, ready to photocopy.
Free with an account (any 3 lessons), or US$19 for all 4 lessons in this unit.
What students show by the end
- Makes equal parts
- Orders unit fractions
- Explains the whole matters
From the lesson’s rubric, which scores each one as not yet, getting there or got it.
Questions teachers ask
How long does “Is half always the same size?” take?
50–60 min. Group size: teams of 3.
How much prep does it need?
15 minutes: cut paper strips from card stock or file folders, 24 cm by 4 cm (about 91/2 in by 11/2 in). Each team needs 6 long strips and 2 short strips of 12 cm by 4 cm, the same width. These are the 'granola bars'. Students write on them, so use a light colour.
What materials do I need?
Paper strips 24 cm by 4 cm (the long bars); paper strips 12 cm by 4 cm (the short bars); 30 cm (12 in) ruler; scissors and a pencil. Cost: free: paper, rulers and scissors you already have.
Which curriculum standards does it cover?
Common Core Math (US): 3.NF.A.1, 3.NF.A.3 and 4.NF.A.2.
What’s in the lesson PDF?
A teacher guide that walks you through predict, hunt, reveal, act, background for the teacher and assessment, then a student sheet (“My prediction”, “Our bars”, “What did we find?”, “My note to Grandpa”, “Exit ticket”, “Label it” and “Try it at home”) on its own page, ready to photocopy. It’s US Letter and prints cleanly in black and white.
Can I try it for free?
Yes. A free account includes any 3 full lessons of your choice, and this can be one of them. After that, this unit is US$19 for all 4 lessons, yours to keep, or every lesson is US$199 a year.