Each time a robin hops, it makes two tracks. Count this robin's tracks by 2's. Count by 2's to 24. 6 8 10 12 14 16 18 20 22 24 2 4 6 Read the following chart in this way: One 2 is 2, two 2's are 4, three 2's are 6, four 2's are 8, and so on. Write columns like the above containing seven 2's, eight 2's, nine 2's, ten 2's, eleven 2's, and twelve 2's. MULTIPLICATION BY TWO Look at the chart on must use 2 to make 4. make 6? To make 8? 85 page 84 to see how many times you How many times must you use 2 to To make 10? Then 3 You see that 2 times 2 is the same as 2 and 2. times 2 means 2 and 2 and 2. What does 4 times 2 mean? What does 5 times 2 mean? What does 6 times 2 mean? When you want to write 2 times 2 are 4 you may write it this way: 2X2=4. How will you write 3 times 2? How will you write 4 times 2? The sign means times. 2×2 means 2 times 2 or 2 multiplied by 2. Read the following multiplication table of 2's. Memorize it. 86 MULTIPLICATION BY TWO 1. George bought 6 stamps at 2 cents each. How much did they cost? 2. Mary put 9 two-cent stamps on a package. How much did the stamps cost? 3. John has 2 apples. Albert has 3 times as many. How many apples has Albert? 4. Sam has 3 pairs of doves. How many doves has he? 5. How much will 8 apples cost at 2 cents each? 6. How much will 9 pencils cost at 2 cents each? 7. How much will 5 newspapers cost at 2 cents each? 8. How much will 7 post cards cost at 2 cents each? Make the following additions: Compare the multiplication table above with the table of 2's on page 85. Note that 2X3=3X2, and so on. If you Use this chart to drill on the table of 2's. Multiply the numbers around the circle by the 2 at the center. have learned the table of 2's you can do this easily. If you cannot make these multiplications quickly, study the tables carefully again. Give the answers for these multiplications orally. When you multiply the answer is called the product. When you multiply one number by another, you may write the numbers like the examples below. Give the products of these multiplications orally: |