70%=70/100=7/10
what you do is shade 7 of the squares and say that is 21
now each square is worth the same
so 21/7=3
each square is worth 3
10 squares
3 times 10 is 30
the number is 30
see diagram
what you do is shade 7 of the squares and say that is 21
now each square is worth the same
so 21/7=3
each square is worth 3
10 squares
3 times 10 is 30
the number is 30
see diagram