IV. Find the product. (See p. 106, prob. 25 and 26.) (d) Find the sum of the ten products. (For a continuation of this work see page 101.) *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. Let a = 2, b = 3, x = 5, and y = 7, and verify. Assign a numerical value to each letter and verify. Observe that in the verification of these problems any value you please may be given to a letter only provided it retains the value given it, throughout the solution of that particular problem. II. Find the quotient and verify as above. 3. The length of a certain rectangular field is thi its breadth; its perimeter is 360rd. What is its 1 its length? NOTE. If its breadth is x feet then its length is 3x feet, and its p 2x+6x feet. Then, 2x+6x= 360. 4. If of the value of a farm is $2154, what is value of the farm? NOTE.-If of a certain number is 21, what is the number? What number? 5. I spent of my money and had $3.60 ren (a) How much did I spend? (b) What I had ren equals what part of what I spent? 6. Change ator is 30. to an equivalent fraction whose de 7. Change to an equivalent fraction whose nu is 30. 8. Change a2 to an equivalent fraction whose den tor is bc. 9. Multiply by and multiply the product by 2 10. Multiply 27 by 18 and multiply the product by 11. If of an acre of land is worth $36, how mu 37 acres worth at the same rate? 12. The rent of a house for 2 yr. 4 mo. was $840. was the rate per year? |