Idea 13of 22Builds onPredict how many times
Tally the spins
How do you keep track of what each spin gives?
Today you'll discover
- how tally marks are bundled
- how to count them quickly
- how to check the total
Think firstThe tally of 20 spins
How many spins landed on orange?
Decide first, then press Next. Count each crossed bundle as 5.
A tally table with a row for orange and a row for blue. Orange has one crossed bundle of five and one mark; blue has two bundles and four marks. A 5 appears under each bundle, then the counts 6 and 14, then the total, 20 spins. The last step shows a table of 30 spins in orange, blue and green.
See the whole ideathe big idea and the key word, in one place
The big idea
A tally table records each result with a mark, bundled in fives so it is quick to count.
Reading a rowTwo crossed bundles and four marks: 5 + 5 + 4 = 14.
Easy to get wrongMake one mark per spin, right after it. Spinning several times and tallying later loses results.
Key word
- tally table
- a table that records results with marks, every fifth mark crossing the four before it
Ready to use it?
- Record spins in a tally table.
- Read the counts from a tally table.