How do you add in base 8 the numbers 6_8, 54_8, 134_8 and 752_8 ?

1 Answer
Oct 18, 2017

6_8+54_8+134_8+752_8 = 1170_8

Explanation:

Write the numbers in a list, right-aligned so we can add up the columns.

color(white)(000)6
color(white)(00)54
color(white)(0)134
underline(color(white)(0)752)

In the units column, add 6, 4, 4 and 2 to get 20_8 (i.e. 16_10). So write a 0 in the units column of the sum and carry 2.

color(white)(000)6
color(white)(00)54
color(white)(0)134
underline(color(white)(0)752)
color(white)(000)0
color(white)(00)color(grey)(2)

In the eights column, add 5, 3, 5 and our carry 2 to get 17_8 (i.e. 15_10). So write a 7 in the eights column of the sum and carry 1.

color(white)(000)6
color(white)(00)54
color(white)(0)134
underline(color(white)(0)752)
color(white)(00)70
color(white)(0)color(grey)(12)

In the eight-squared column, add 1, 7 and our carry 1 to get 11_8 (i.e. 9_10). So write a 1 in the eight-squared column of the sum and carry 1.

color(white)(000)6
color(white)(00)54
color(white)(0)134
underline(color(white)(0)752)
color(white)(0)170
color(grey)(112)

In the eight-cubed column, we just have our carry 1, so write that in the eight-cubed column of the sum and stop.

color(white)(000)6
color(white)(00)54
color(white)(0)134
underline(color(white)(0)752)
1170
color(grey)(112)