So I was playing Yahtzee and I rolled two twos on the dice. And somehow I write 10 in that column. In what world does 2+2=10???
well not 2 + 2
but 2 in binary is written as 10
and binary is base 2
so if instead of 2 + 2
it was (2) in base (2) it would be = 10
2 as you got it is also in the decimal representation, which is base 10, so that too
for decimal representation 2 digits:
first digit is 10 (base)^1 so tens place
second digit is 10 (base) ^ 0 (1) so ones place
so 2 is 0 * 10^1 + 2 * 10^0 (1) = 2
and 10 is 1 * 10^1 + 0 * 10^0 (1) = 10
binary representation 2 digits:
first digit is 2(base)^1 so twos place
second digit is 2 (base)^0 (1) so ones place
so 10 in binary is 1 * 2^1(2) + 0 * 2^0(1) = 1 * 2 + 0 * 0 = 2 in decimal representation
for any base representation system, each "place" starting from the very right (before any decimal point if any) is the base raised to (how many places it is from the rightmost/ones place)
so like for 10 (decimal) in binary
4 digits
1010
1 0 1 0
2 ^ 3 place (8s place), 2 ^ 2 place (4s place), 2 ^ 1 place (2s place), 2 ^ 0 place (1s place)
so 1010 in binary is 10 in decimal bc
1 * 2 ^ 3 + 0 * 2 ^ 2 + 1 * 2 ^ 1 + 0 * 2 ^ 0 = 1 * 8 + 0 * 4 + 1 * 2 + 0 * 1 = 8 + 2 = 10
one 8, one 2
like for 4 digits in decimal we have
10 ^ 3 place (thousands place), 10 ^ 2 (hundreds place), 10 ^ 1 (tens place), 10 ^ 0 (ones place)
this place value is the same for any base
like if we had base 3, 4 digits would be
3 ^ 3 place (27s place), 3 ^ 2 place (9s place), 3 ^ 1 place (3s place), 3 ^ 0 place (1s place)
converting from decimal to any base is first dividing the number by the base and keeping track of the remainder
step 1, 10 to binary: 10 / 2 = 5 R0
step 1, 10 to base 3: 10 / 3 = 3 R1
then you divide the quotient by the base, and keep track of the remainder, and keep doing this until the quotient becomes 0
10 to binary:
- 5 / 2 = 2 R1
- 2 / 2 = 1 R0
- 1 / 2 = 0 R1
10 to base 3:
- 3 / 3 = 1 R0
- 1 / 3 = 0 R1
then the converted decimal number in the new base representation, is the remainders written in from most recent (reverse order of you getting them)
so 10 in binary = 1010 (showed already)
and 10 in base 3 = 101
Check?
1 * 3 ^ 2 (9s place) + 0 * 3 ^ 1 (3s place) + 1 * 3 ^ 0 (1s place) = 1 * 9 + 0 * 3 + 1 * 1 = 9 + 1 = 10
but for 2 + 2 = 10 exactly and specifically
we know 2 + 2 = 4
so then 10 must be equal to 4
how would that work? what base?
the 1 is in the (base) ^ 1 place (which is just the base) and the 0 is in the (base) ^ 0 place (which is just the ones place)
so 1 * base = 4,
so the base is 4, 10 in base 4 is 4 in decimal representation
the decimal representation 2 is still 2 in base 4, because it is one digit and in the ones place
so is 2 (base 4) + 2 (base 4) = 10 (base 4)?
yes because we end up carrying.
The ones place in any base representation goes from 0 to the (base - 1) before, requiring another digit and being carried to the next place
For example, for decimal representation, base 10, the ones place goes from 0 - 9, and 10 requires 2 digits. In fact, for any place, the digits we can use are 0 - 9, and for any base representation, the digits we can have in any place, not just ones place, are 0 - (base - 1)
9 is 9 * 10^(0) (1)= 9 * 1 = 9
10 is 1 * 10^1 (10) + 0 * 10^0 (1) = 1 * 10 + 0 * 1 = 10
so adding 2 and 2 in base 4 gets 10 in base 4, 1 * 4 + 0 * 1 = 4 + 0 = 4
for base 4, the digits we have are 0 - 3
so the world in which 2 + 2 = 10 is base 4
I forgot about that being true in base 4 at first hence the binary explanation bc I thought 10 in binary is 2 right away
another conversion, if it helps make it sense?
10 (in decimal) to base 4
10 / 4 = 2 R2
2 / 4 = 0 R2
10 (in decimal) = 22 in base 4
Check/Proof:
2 * 4^1 + 2 * 4^0
2 * 4 + 2 * 1
8 + 2
10
10 = 10
lemme know if anything didn't make sense