Find missing num 100 down  Learn  Contents and Search  Practice  Next Lesson  Play  Previous Lesson  Explore   Feedback Practice Your Spelling List States of the United States Nations of the World   Finding a Missing Number in a Sequence How to find a missing number in a sequence Determine if the order of numbers is ascending (getting larger in value) or descending (becoming smaller in value). Find the difference between numbers that are next to each other. Use the difference between numbers to find the missing number. Example: Find the missing number: 15, 13, ?, 9 The order of numbers is going down or descending. The difference between numbers is 15 - 13 = 2 Since the order is descending subtract 2 from 13. The missing number may be 11. The missing number is 11 since it is 2 more than the last number 9. Return to Top Share Practice Find the Missing Number Note: The number order may go either up or down! You have correct and   incorrect.  This is percent correct. Return to Top Tell Others About This Site AAASpell.com Practice Your Spelling List Practice Our Spelling Lists Vocabulary Practice Alphabet Practice Play Game What is it? Best Score How many correct answers can you get in 60 seconds? Extra time is awarded for each correct answer. Play longer by getting more correct. How fast can you get 20 more correct answers than wrong answers? Sudoku Timez Attack Multiplication Video Game Return to Top Explore Math Lessons by Grade Kindergarten  First Second Third Fourth Fifth Sixth Seventh Eighth Math Topics Addition Algebra Comparing Counting Decimals Division Equations Estimation Exponents Fractions Geometry Graphs Measurement Mental Math Money Multiplication Naming Numbers Patterns Percent Place Value Practical Math Properties Ratios Statistics Subtraction Math Resources Schools Teachers Parents Home Schooling Web Resources Spelling Lessons by Grade First Second Third Fourth Fifth Sixth Seventh Eighth or - Practice Your Word List Vocabulary Lessons by Grade First Second Third Fourth Fifth Sixth Seventh Eighth Geography States of the United States Nations of the World Geographical Photos WorldPlenty.com What will the future be like? Other Interests Music DVD Computer and Video Games Books Sports Toys and Games Return to Top About This Site Frequently Asked Questions Send Us Feedback About this Site Privacy Policy Purchase The Math Class CD Share| Return to Top