Find the products of:

172. 2, 3, 4, 5, 7, 8, 9, by 2

173. 1, 5, 6, 7, 4, 3, 8, by 4

174. 8, 7, 6, 4, 5, 3, 2, by 5
175. 12, 11, 10, 8, 9, 7, 6, by 6
176. 5, 6, 8, 7, 2, 3, 4, by 7
177. 3, 2, 5, 8, 9, 10, 11, by 3
178. 9, 8, 6, 7, 4, 5, 12, by 8
179. 10, 11, 12, 9, 8, 7, 6, by 9
180. 2, 3, 4, 9, 10, 11, 12, by 10
181. 9, 8, 7, 6, 5, 4, 3, by 11
182. 10, 12, 9, 11, 7, 6, 3, by 12
183. 12 by 1, 2, 6, 7, 8, 9
184. 9 by 3, 4, 7, 2, 5, 6

Read the products rapidly:

282. 1x 2; 10 x 2; 100 x 2; 1000 x 2.

283. 20 x 2; 30 x 2; 40 × 2; 50 x 2; 60 × 2; 80 × 2. 284. 5×4; 50×4; 500×4; 5000 × 4; 60×4; 600 × 4. 285. 7×5; 70×5; 700×5; 7000 × 5; 80×5; 800×5. It will be observed that the product of 7 by 5 is the same, whatver order of units 7 may represent.

286. 700×6; 600 × 7; 900 × 4; 500×9; 400 x 8.

287. 2000 x4; 5000 x7; 3000 x 8; 8000 x 5.

288. Multiply 20, 200, 2000, by all the numbers from to 9 inclusive.

289. Multiply 30, 300, 3000, by the same multipliers in the preceding example.

290. In the same manner proceed with all the similar umbers to 90, 900, 9000.

PROBLEMS.

21. 1. At $9 a ton, how much will 3 tons of hay cost?

SOLUTION.

·3 × $9 $27. Three tons of hay will cost $27. 2. At 8 cents a quart, how much will 4 quarts of blueberries cost?

3. If you answer 11 questions at each recitation, how many questions will you answer at 3 recitations? at 4? 4. What is the cost of 4 pairs of shoes, at $3 a pair?

5. If a ream of paper costs $3, how much will 2 reams cost? 3 reams? 4 reams?

6. Eight quarts make a peck. How many quarts are there in 3 pecks? in 4 pecks? in 5 pecks?

7. At 12 cents a yard, how much will 3 yards of cloth cost? 4 yards?

8. If you recite 8 perfect lessons every week, how many will you recite in 5 weeks? in 6 weeks? in 7 weeks?

9. How much will 6 pounds of sugar cost, at 5 cents a pound? at 6 cents?

10. If you write 5 lines a day, how many lines will you write in 4 days? in 7 days?

11. What is the cost of 5 yards of ribbon, at 8 cents a yard? at 9 cents?

12. What is the cost of 7 barrels of apples, at $2 a barrel?

13. At $12 a ton, how much will 6 tons of hay cost? 7 tons? 5 tons?

14. If a boat sails 9 miles an hour, how far will she sail in 4 hours? in 6 hours? in 7 hours?

15. How much will 7 barrels of flour cost, at $6 a barrel?