Lesson 2 of 14
Share it out equally
Show on a big screenRain in five months: 90, 110, 100, 130 and 70 mm. A mm, or millimetre, is a tiny length. How wet were the five months? Give one number.
Loading lab…
Step 1 of 2
- Five months, five heights: 90, 110, 100, 130, 70 mm.
- Move blocks until every stack is 100 mm.
One number for the five months is 100 mm a month.
Add all the readings. Share the total equally. That share is the mean. It is also called the average.
Moving blocks never changes the total. 90 + 110 + 100 + 130 + 70 = 500. There are 5 months, so we need 5 equal shares. Then 500 ÷ 5 = 100 mm.
Sharing equally may not give a whole number. Four crates hold 2, 3, 4 and 6 mangoes. The total is 2 + 3 + 4 + 6 = 15. Then 15 ÷ 4 = 3.75.
Watch out!
No crate holds 3.75 mangoes. That is fine. The mean is the size of one share.
Try the lab to finish this lesson.