Friday, November 28, 2008
Lesson 5 - Factors, Multiples, and Divisibility

This lesson consists of giving you the necessary "preliminaries" to do fractions. The tutor explains what are factors, divisors, prime and composite numbers, how to do prime factorization, GCFs, LCMs, multiples, and the rules of divisibility. He also explains how to use your graphing calculator to help you find the GCF, LCM and multiples.
PDF File here
Go to the Fraction section to get lesson 6.
Monday, November 24, 2008
First Lessons in Arithmetic: Lesson XXII. - Basic Subtraction
Friday, November 21, 2008
Lesson XXI - Basic Subtraction
1. Helen had 3 cents, and bought a pencil with it.
Q: How much money does she have now?
C: 3-3=_
A:
2. A man had 4 horses, and sold 3 of them.
Q: How many horses does he have
left?
C: 4-3=_
A:
3. There are 5 cows in a field, and 3 are sold.
Q: How many cows are left?
C: 5-3=_
A:
4. A boy had 6 marbles, and gave 3 away.
Q: how many marbles does he have left?
C: 6-3=_
A:
5. Sally had 7 dollars and bought a pencil case for 3 dollars.
Q: How much money does Sally have left?
C:7-3=_ A:
6. A woman had 8 dollars, gave 3 away for a hat.
Q: How much money does she have left?
C: 8-3=_
A:
7. There were 9 hoses in a field, 3 of them were taken to the barn.
Q: How many horses are in the field now?
C: 9-3=_
A:
8. If there were 10 pigeons on a limb, and 3 flew away.
Q: How many pigeons were still on the limb?
C: 10-3=_
A:
9. a) 11-3=_ b) 12-3=_
10. If James had 4 apples, and gave away 4.
Q: How many apples does James have now?
C: 4-4=_
A:
11. If Emily had 5 cents, and gave 4 cents for paper.
Q: How much money does she have now?
C: _ - _ = _
A:
12. a) 6 - 4 = _ b) 7 - 4 =_
13. a) 8 - 4 = _ b) 9 - 4 = _
c)10 - 4 = _ d) 11 - 4 = _
14. a) 12 - 4 = _ b) 13 - 4 = _
15. Form the subtraction tables of threes and fours.