1. The problem involves counting tens and units from given tally marks. 2. For example, |||||||| |||||| |||| means 8 tens + 6 tens + 4 units. 3. The formula for tens and units is: Number = (Tens \times 10) + Units. 4. For 23, it is 2 tens and 3 units. 5. Shade half means shading 1/2 of a shape; one-quarter means shading 1/4. 6. Arrange numbers from biggest to smallest by comparing their values. 7. 1/4 of 8 cups means dividing 8 by 4, which equals 2. 8. Expanded form means writing numbers as sums of hundreds, tens, and units. 9. Addition problems are solved by adding digits in units and tens place. 10. Even numbers are divisible by 2; odd numbers are not. 11. Counting in 20s from 5 means adding 20 repeatedly starting at 5. 12. Examples of odd numbers are 5, 7, 9, 31, 37, 41. 13. Adding without exchanging means adding digits without carrying over. 14. Fraction problems: a. 3/4 of 28 balls = $$\frac{3}{4} \times 28 = 21$$ b. 1/4 of 40 pens = $$\frac{1}{4} \times 40 = 10$$ c. 1/2 of 10 tables = $$\frac{1}{2} \times 10 = 5$$ 15. Counting in 10s from 1 to 21: 1, 11, 21. 16. Counting in 10s from 2 to 102: 2, 12, 22, ..., 102. 17. Counting in 20s from 4 to 124: 4, 24, 44, 64, 84, 104, 124. This covers all the problems in the sections.