II. Find the product. (See p. 245, problems 21 and 22.) IV. Find the product. (See p. 246, problems 25 and 26.) 5. 523 × 2. 8. 153 × 8. 6. 5232 × 2. 9. 1531 × 2. (d) Find the sum of the ten products. * Take 3 times 1 tenth of 345, or 1 tenth of 3 times 345. + Lead the pupil to see that in problems of this kind the correct result may be obtained by "multiplying the numerators together for a new numerator and the denominators together for a new denominator"; that in so doing he divides the multiplicand by the denominator of the multiplier and multiplies the quotient so obtained by the numerator of the multiplier. Observe that in cases like the above, in which the denominators are prime to each other, the 1. c. d. is the product of the given denominators, and each new numerator may be found by multiplying the given numerator by the denominator of the other fraction. 21 ÷ 7 = 3. 5X3 15 7 x 321 = 14 15 29 + 21 21 21 Assign a numerical value to each letter and verify. SOLVE. Then let x = 5 and y = 7 and verify. 194. Miscellaneous Review. 1. A piece of land in the form of an equilateral triangle measures on one side 46 rods. What is the distance around it? 2. The perimeter of a piece of land that is an exact square is 2463 feet. How far across on one side? 3. The length of a certain rectangular field is three times its breadth; its perimeter is 360 rd. What is its breadth ? Its length? 4. If of the value of a farm is $2154, what is of the value of the farm? NOTE. If of a certain number is 24, what is the number? What is of the number? 5. I spent of my money and had $3.60 remaining. (a) How much did I spend? (b) What I had remaining, equals what part of what I spent? 6. Change to an equivalent fraction whose denominator is 30. 7. Change to an equivalent fraction whose numerator is 30. a2 8. Change to an equivalent fraction whose denomi b nator is bc. 9. Multiply by 3 and multiply the product by 25. 10. Multiply 37 by 13 and multiply the product by 25. 11. If of an acre of land is worth $36, how much are 37 acres worth at the same rate? 12. The rent of a house for 2 yr. 4 mo. was $840. What was the rate per year? |