Doubling and Halving
What is an equivalent equation for 4 x 18 =
Also provide the answer
4 x 18 = 8 x 9
= 72
What is the answer to 5 x 9?
Use a landmark number and adjust!
5 x 10 = 50
50-5 = 45
What is the volume of a building with...
Base = 5
Width = 3
Height = 10
(5 x 3) x 10 =
15 x 10 = 150
A building has a height of 3, a width of 2, and a base of 5.
What expression can be written?
(5 x 2) x 3
What is an equivalent equation to 12 x 8=
Also provide the answer
12 x 8 = 6 x 16
= 96
What is 11 x 8?
Use a landmark number and adjust!
10 x 8= 80
80 + 8= 88
What is the volume of a building with a base of 12, a width of 4, and a height of 2?
(12 x 4) x 2
48 x 2 = 96
A building has a base of 12, a height of 6, and a width of 9. What expression can be written?
(12x9)x6
What is an equivalent fraction to the equation
50 x 20=
50 x 20 = 100 x 10
= 1,000
What is 15 x 9?
Use a landmark number and adjust!
15 x 10 = 150
150 - 15 = 135
Base=12
Width=2
Height=3
(12 x 2) x 3
24 x 3 =72
Miss Weidel found the answer to 9 x 14 by using a landmark number of 10 and subtracting a group of 14. What expression can be written?
(10x14) - (14x1)
What is an equivalent equation to
24 x 10 =
24 x 10 = 12 x 20
=240
What is the answer to 20 x 19?
Use a landmark number and adjust!
20 x 20 = 400
400-20=380
One building has a base of 8, a width of 4, and a height of 10. Another building has a base of 6, a width of 3, and a height of 5. What is the total volume?
(8x4)x10
32x10=320
(6x3)x5
18x5=90
320 + 90 = 410 cubic units
Dude found the answer to 38 x 4 by using a landmark number of 40 and then subtracting two groups of 4. What expression can be written?
(40 x 4) - (2 x 4)
(40 x 4) - 8