There are several ways to solve the following exercise,
We will present two of them.
In both ways, we begin by decomposing the number 84 into smaller units; 80 and 4.
44โ=1
Subsequently we are left with only the 80.
Continuing on with the first method, we will then further decompose 80 into smaller units; 10ร8
We know that:48โ=2
And therefore, we are able to reduce the exercise as follows: 410โร8
Eventually we are left with2ร10
which is equal to 20
In the second method, we decompose 80 into the following smaller units:40+40
We know that: 440โ=10
And therefore: 440+40โ=480โ=20=10+10
which is also equal to 20
Now, let's remember the 1 from the first step and add it in to our above answer:
20+1=21
Thus we are left with the following solution:484โ=21