Number Theory flashcards
17 practice cards drawn from the Number Theory lessons. Tap a card to turn it over. Every answer is checked against the lesson it came from.
Read the Number Theory lessons in full →
Multiply 2 × 3 × 5 × 7 × 11 and add 1. What do you get?
2311
from “Euclid’s Proof That Primes Never Run Out”
Multiply 2 × 3 × 5 × 7 and add 1. What do you get?
211
from “Euclid’s Proof That Primes Never Run Out”
What is 13 mod 5?
3
from “Modular Arithmetic on a Clock Face”
What is 31 mod 12?
7
from “Modular Arithmetic on a Clock Face”
What is 829 mod 9?
1
from “Casting Out Nines to Check Arithmetic”
What is 447 mod 9?
6
from “Casting Out Nines to Check Arithmetic”
Does stop or recur?
stops
from “Why Every Fraction Terminates or Recurs”
Does stop or recur?
recurs
from “Why Every Fraction Terminates or Recurs”
0.666… recurring is which fraction?
from “Why 0.999… Equals Exactly One”
0.333… recurring is which fraction?
from “Why 0.999… Equals Exactly One”
0.888… recurring is which fraction?
from “Turning Recurring Decimals into Fractions”
0.555… recurring is which fraction?
from “Turning Recurring Decimals into Fractions”
What is the biggest unit fraction that fits inside ?
from “Egyptian Fractions and the Greedy Algorithm”
What is the biggest unit fraction that fits inside ?
from “Egyptian Fractions and the Greedy Algorithm”
If a is odd, what follows?
is odd
from “The Square Root of Two Is Irrational”
If is even, what follows?
a is even
from “The Square Root of Two Is Irrational”
Work this continued fraction out
from “Continued Fractions”