Multiplication
What does the number sentence 4 X 6 mean?
The number sentence 4 X 6 means
4 groups of 6
There are 4 rows with 6 in each row.
Use rounding to estimate and then solve.
Estimate: ____ + _____ =____
Solve: 326 + 72 = ___
Estimate:
300 + 70 = 370 OR 330 + 70 = 400
Solve: 326 + 72 = 398
What is the turn-around rule for
3 X 4 __ X __
The turn-around rule for
3 X 4 is 4 X 3
RULE: __?__ (What's the Rule?)
IN OUT
3 6
4 7
28 31
RULE: _Add 3__
IN OUT
3 6
4 7
28 31
Vicki doesn't know 9 X 3. What is a helper fact that she could use to help her figure out the answer?
A helper fact for 9 X 3 can be 9 X 2.
She could use 9 X 2 because she can count 9 groups of 2 and get 18. Then she can add one more group of 9 to get 27 9 X 2 = 18 + 9 = 27, so 9X3 = 27.
Solve
3 X 8 = ? (You can draw an array to help you)
Answer: 3 X 8 = 24
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
Use rounding to estimate and then solve.
Estimate: ____ - ______ =______
Solve: 86 - 42 = ________
Estimate: 90 - 40 = 50 OR 100 - 40 = 60
Solve: 86 - 42 = 44
Write a number sentence to match each array.
A. X X X X X X X B. X X X
X X X X X X X X X X
X X X
A. X X X X X X X B. X X X
X X X X X X X X X X
X X X
2 X 7 = 14 3 X 3 = 9
RULE: Multiply by 2
IN OUT
3 6
4 ___
___ 10
RULE: Multiply by 2
IN OUT
3 6
4 _8_
_5_ 10
James doesn't know 6 X 8. What is a helper fact that he could use to help him figure out the answer?
A helper fact for 6 X 8 can be 5 X 8.
She could use 5 X 8 because he can count 5 groups of 8 and get 40. Then he can add one more group of 8 to get 48. 5 X 8 = 40 + 8 = 48, so 6X8 = 48.
Draw an array to show 3 rows of chairs with 6 chairs in each row. How many chairs do you have in all?
3 rows of chairs with 6 chairs in each row. 3 X 6 = 18 chairs in all
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
Use rounding to estimate and then solve.
Estimate: ____ + _____ =____
Solve: 169 + 28 = ___
Estimate:
200 + 30 = 230 OR 170 + 30 = 200
Solve: 169 + 28 = 197
Draw an array to help you solve this problem
3 X 4 =?
The array for 3 X 4 is
X X X X
X X X X
X X X X
3X4=12
RULE: ADD 8
IN OUT
16 24
32 ___
__ 48
RULE: ADD 8
IN OUT
16 24
32 _40_
_40_ 48
Julie doesn't know 3 X 7. What is a helper fact that she could use to help her figure out the answer?
A helper fact for 3 X 7 can be 2 X 7.
She could use 2 X 7 because she can count 2 groups of 7 and get 14. Then she can add one more group of 7 to get 21. 2 X 7 = 14 + 7 = 21, so 3X7 = 21.
Draw an array to show 4 rows of flowers with 7 flowers in each row. How many flowers do you have in all?
4 rows with 7 flowers in each row. 4X7=28 flowers in all
X X X X X X X
X X X X X X X
X X X X X X X
X X X X X X X
Use rounding to estimate and then solve.
Estimate: ____ + _____ =____
Solve: 326 + 72 = ___
Estimate:
200 + 30 = 230 OR 170 + 30 = 200
Solve: 169 + 28 = 197
Draw an array to help you solve this problem
2 X 6 =?
The array for 2 X 6 is
X X X X X X
X X X X X X
2X6=12
RULE: Subtract 6
IN OUT
13 7
24 ___
___ 20
RULE: Subtract 6
IN OUT
13 7
24 _18
_26_ 20
Susan doesn't know 3 X 6. What is a helper fact that she could use to help her figure out the answer?
A helper fact for 3 X 6 can be 3 X 5.
She could use 3 X 5 because she can count 3 groups of 5 and get 15. Then she can add one more group of 3 to get 18. 3 X 5 = 15 + 3 = 18, so 3X6 = 18.
What does the number sentence 10 X 9 mean?
The number sentence 10 X 9 means
10 groups of 9
There are 10 rows with 9 in each row.
Use rounding to estimate and then solve.
Estimate: ____ - _____ =____
Solve: 293 - 85 = ___
Estimate:
300 - 90 = 210 OR 300 - 100 = 200 OR
290 - 100 = 190 OR 290 - 90 = 200
Solve: 293 - 85 = 208
Draw an array to help you solve this problem
3 X 10=?
The array for 3 X 10 is
X X X X X X X X X X
X X X X X X X X X X
X X X X X X X X X X
3X10=30
RULE: ADD 100
IN OUT
8 108
10 ___
___ 119
RULE: ADD 100
IN OUT
8 108
10 _110_
_19_ 119
Bob doesn't know 9 X 6. What is a helper fact that he could use to help him figure out the answer?
A helper fact for 9 X 6 can be 9 X 5.
He could use 9 X 5 because he can count 9 groups of 5 and get 45. Then he can add one more group of 9 to get 54. 9 X 5 = 45 + 9 = 54, so 9X6 = 54.