Mathematics
Grade 2
15 min
Mean, median, mode, and range: find the missing number
Mean, median, mode, and range: find the missing number
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1
Introduction & Learning Objectives
Learning Objectives
Use multiplication to find the total sum when given the mean.
Find a missing number in a small data set using the mean.
Identify the missing number in an ordered list using the median.
Find a missing number in a small data set using the mode.
Find a missing number (highest or lowest) using the range.
Explain the difference between mean, median, and mode.
Oh no! 😱 One of our numbers is hiding! Can you be a math detective and find it?
We will learn about four math clues: mean, median, mode, and range. These clues will help us find the missing number in a group. We will even use multiplication to help us!
Real-World Applications
Sharing cookies fairly with friends 🍪
Finding the most popular toy in a class 🧸
Figuring out the middle height in a lin...
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Key Concepts & Vocabulary
TermDefinitionExample
Mean (or Average)The mean is what each person gets if we share everything equally. 🍎🍎🍎If 3 friends share 6 cookies, the mean is 2 cookies each (6 ÷ 3 = 2).
MedianThe median is the number that is right in the middle of a line. ↔️In the numbers 1, 5, 9, the median is 5 because it's in the middle.
ModeThe mode is the number you see the most often. 👀In the numbers 2, 8, 2, 5, the mode is 2 because it appears most.
RangeThe range is the difference between the biggest and smallest number. 🐘➖🐁For the numbers 3, 5, 10, the range is 10 - 3 = 7.
Missing NumberThe missing number is a secret number we need to find. ❓In the group 2, 4, ?, 8, the question mark is the missing number.
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Core Formulas
Mean and Multiplication Rule
\text{Total Sum} = \text{Mean} \times \text{How Many Numbers}
To find the total of all numbers, multiply the mean by how many numbers are in the group.
Find the Missing Number (Mean) Rule
\text{Missing Number} = \text{Total Sum} - \text{Sum of Known Numbers}
After you find the total sum, subtract the numbers you already know.
Find the Biggest Number (Range) Rule
\text{Biggest Number} = \text{Smallest Number} + \text{Range}
If you know the smallest number and the range, add them to find the biggest number.
4 more steps in this tutorial
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Challenging
A list has three numbers. The 'mean' is 10, so the total is 3 x 10 = 30. The mode is 12. What is the smallest number in the list?
A.6
B.8
C.10
D.12
Challenging
A list has five numbers. The smallest number is 5. The range is 2 x 3 = 6. The median is 8. The mode is 8. What is the largest number?
A.8
B.11
C.6
D.14
Challenging
The 'mean' of 3 numbers is 7 (so the total is 21). The median is 8. One of the numbers is 5. What is the largest number?
A.7
B.5
C.8
D.21
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