10. Practice in Adding with Sums 10 or Less.* (RAPID ORAL PRACTICE.) Give the sums of the following examples. "Give the sums" means the same thing as "add the numbers." Practice until you can give all of the sums without making a mistake. These examples are arranged in rows, and each row is numbered. How many rows are there? Take turns in giving the sums for each row. Watch carefully while other pupils are trying. If a mistake is made, put up your hand. If you cannot give all the sums quickly, turn to page 368 and practice on the addition facts at home and at other times in school. *TO THE TEACHER: See Teacher's Note 2. NEW WORK WORDS AND FIGURES IN ARITHMETIC 13 11. Words and Figures in Arithmetic. (SILENT READING.) There are different ways of writing numbers. Sometimes they are written in words, and sometimes in figures. "Figure" is a new word. Try to find out from this lesson what it means. Some numbers are written with only one figure. Numbers like 3, 4, 6, and 9 are one-figure numbers. But other numbers have more than one figure in them. 5. Twenty-seven is a word. 27 is a two-figure number. 6. Is 36 a one-figure or a two-figure number? 7. Is 8 a two-figure number? 8. How many figures are needed to write the number eight? 9. How many figures are needed to write the number eighteen? 10. There are two figures in 47. 11. There are two figures in 19. they are? They are 4 and 7. Can you tell what 12. Name the figures in 34. In 56. In 28. Write on your paper the figures that belong in the blanks below. Look at Example 13. It shows how to write the correct figure. Your teacher may ask you to write these figures on the blackboard. ADDITION WITH SUMS 11 TO 18 12. Harder Addition. (ORAL PRACTICE.) Can you give the answers to the 36 examples in this lesson? Try them and see. If you can't tell the sums quickly, turn to page 369 and practice. Then try this lesson again. Notice that these examples are printed in column form. NEW WORK 13. Zero in Addition. (CLASS WORK.) There are only ten figures used in arithmetic. Here they are. 0 1 2 3 4 5 6 7 8 9 Do you know the name of the first one? It is called zero. It means not any at all. If you add zero to 5, that is the same as adding nothing to 5. The sum is 5. 5 and 0 are 5. 0 and 9 are 9. 18 and 0 are 18. The 14. Ladder Addition Drill. (ORAL DRILL.) third-grade children like to see how far they can climb on addition ladders. Joe, Billy, and Jack are three boys who like to race. When a pupil does not know the answer or misses one, the children say he falls off |