1ft : 12in → 12ft : 144in
1in : 12ft = 1in : 144 in
{there are 12 inches in 1 foot, so multiply your feet by 12 to get inches}
1m : 100cm → 15m : 1500cm
1cm : 15m = 1cm : 1500cm
{there are 100 centimetre in 1 metre, so multiply your metres by 100 to get centimetres}
1yd : 3ft → 1yd : 75ft
1ft : 12in → 75ft : 900in
1in : 25yd → 1in : 900in
{there are 3 feet in 1 yard, so multiply your yards by 3 to get feet. THEN, there are 12 inches in 1 foot, so multiply your feet to get inches}
OR
1yd : 3ft → 1ft : 12in → 1yd : 36in
25yd : 900in
1in : 900in
{there are 3 feet in 1 yard and 12 inches in 1 foot, so multiply 3 by 12 to get 36 inches in 1 yard. THEN, multiply 25 yards by 36 inches per yard to get 900 inches.}Source(s):Self (Maths teacher)
hopes this helps :) :D :)