4. Tính bằng cách thuận tiện. a) \( 25360+5300+4700+4540= \)

Find the reciprocals of the numbers below. The reciprocal of 2 is \( \square \). The reciprocal of \( \frac{9}{10} \) is \( \square \).

21. By selling a tie for ₹ 252 , a shopkeeper gains \( 5 \% \). At what price should he sell the tie to gain \( 35 \% \) ? 22. A shopkeeper sells a bag at \( 12 \% \) profit. If he had sold it for ₹ 39 more, he would have made \( 18 \% \) profit. Find the cost price of the bag for the shopkeeper.

Round 54 to the nearest ten.

Find the reciprocals of the numbers below. The reciprocal of \( \frac{7}{11} \) is \( \square \). The reciprocal of 4 is \( \square \).

What is 7.8 rounded to the nearest integer?