Welcome to numbersense.org!

The website of the 2024-2025 River Bend Number Sense team

Our team: "Evelyn","Bob","Hieu","Miles","Noah"

Test yourself now!
Puzzlers
In a class election, Bob won and got ten more votes than second-place Rebecca. Rebecca got 6 more votes than Elizabeth, who was last.
  1. What is the minimum number of students in the class?
  2. If there were actually 34 students in the class, how many votes did each candidate get?
Farmer Fred raises chickens and pigs, and keeps them in one big pen at his farm. If there are 12 heads and 40 feet in the pen, how many chickens and pigs does he have?
What's the next number is this sequence? 0,1,5,14,30,______
I have 17 red socks in my drawer and 5 blue socks. If my room is dark in the morning and I can't see the colors, how many socks do I need to take out of the drawer to be sure I have a pair that matches?
Suppose there is a bag with four coins in it: a penny, a nickel, a dime and a quarter. If I randomly pick two coins (and I can't tell the coins apart by feeling them), what is the chance that I pick exactly 26 cents?

Selection of old exams

2018-2019 2019-2020 2020-2021 2021-2022 2022-2023 2023-2024
Exam A
Exam B
Exam C 		Exam A
Exam B
Exam C 		Exam A
Exam B
Exam C 		Exam A
Exam B
Exam C
Date What we covered
Thu, November 7, 2024

Introductions. Questions and Answers. Some quick and fun shortcuts.

Where do numbers come from? How big is zero?

Look around you. Numbers (and patterns) are everywhere!

Today we learned how to multiply two-digit numbers
Tue, November 9, 2024

Review of last time.

How to add a whole bunch of numbers in a row!

This is the order of questions in the Number Sense Contest!

Handout
Thu, November 11, 2024

Finding the remainders of numbers divided by 2,3,4,5,9 and 10. Review.

Sample test 1
Thu, November 16, 2024

Review of last time.

More multiplying!

  • Multiply 25, 50, 75
  • Multiply 33 1/3, 12 1/2, 16 2/3

Multiply by 25, 50, 75 etc
Sample test 2
Thu, November 21, 2024

Review of last time.

Multiplying!

  • Multiply two numbers ending with a 1
  • The distributive property: Splitting numbers apart and putting them back together
  • Multiply two numbers just under 100
  • Multiply two numbers just over 100

Handout
Tue, November 23, 2024

Review of last time.

Multiplying numbers just below, and just above, 100
...not as hard as you think!

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