There is two ways you can prove this:
1. You can prove it using decimals
6.66666667 ~= 6.6666 so,
10*.6666 = 6.6666
6.666 = 6.666 ✔
2. You can prove it using fractions
10/1*4/6 = 6 2/3
10/1*2/3 = 6 2/3
20/3 = 6 2/3
20/30 = 20/30 ✔
Using fractions probably gives you a better visual.
Does this answer your question?
There is two ways you can prove this:
1. You can prove it using decimals
6.66666667 ~= 6.6666 so,
10*.6666 = 6.6666
6.666 = 6.666 ✔
2. You can prove it using fractions
10/1*4/6 = 6 2/3
10/1*2/3 = 6 2/3
20/3 = 6 2/3
20/30 = 20/30 ✔
Using fractions probably gives you a better visual.
Does this answer your question?