Related Facts
2, 3, 6
2 x 3 = 6
3 x 2 = 6
6 ÷ 2 = 3
6 ÷ 3 = 2
20 x 6
20 x 6 = 120
The Onceler can make 11 thneeds from every truffula tree he chops down. If he chops 799 truffula trees before the Lorax stops him, about how many thneeds can the onceler make?
799 trees x 11 thneeds
Round --> 800 x 10
The onceler can make about 8000 thneeds
42
x 3
-------
42
x 3
-------
126
93 ÷ 3
93 ÷ 3 = 31
4, 32, 8
4 x 8 = 32
8 x 4 = 32
32 ÷ 4 = 8
32 ÷ 8 = 4
30 x 7
30 x 7 = 210
Mortimer's parents could not get him to be quiet! They sent all 17 of his siblings upstairs to shush him but it still wasn't enough! Mortimer finally fell asleep after all of his siblings went upstairs 4 times each. About how many times was Mortimer told to be quiet?
17 siblings x 4 times
Round --> 20 x 5
Mortimer was told to be quiet about 100 times
37
x 6
-------
37
x 6
-------
222
38 ÷ 2
38 ÷ 2 = 19
42, 6, 7
6 x 7 = 42
7 x 6 = 42
42 ÷ 6 = 7
42 ÷ 7 = 6
68 ÷ 4
68 ÷ 4 = 17
The Ghost of John has a collection of scary books. If his library has 17 shelves and each shelf holds 87 books, about how many books does the Ghost of John have in his collection?
17 shelves x 87 books
Round --> 20 shelves x 90 books
20 x 90 = 1800
The Ghost of John has about 1800 scary books in his collection.
89
x 21
-------
89
x 21
-------
1869
143 ÷ 3
143 ÷ 3 = 47 r 2
30, 180, 60
30 x 60 = 180
60 x 30 = 180
180 ÷ 60 = 30
180 ÷ 30 = 60
56 ÷ 8
56 ÷ 8 = 7
Morah Halley ordered cupcakes for her 18 friends, but the bakery mixed up her order and gave her 80 cupcakes instead! About how many cupcakes could each friend eat?
Round 18 --> 20
80 ÷ 20 = 4
Each of Morah Halley's friends could eat about 4 cupcakes.
450
x 13
-------
450
x 13
-------
5850
306 ÷ 4
306 ÷ 4 = 76 r 2
0, 7, 0
0 x 7 = 0
7 x 0 = 7
0 ÷ 7 = 0
7 ÷ 0 = *Undefined*
*You can't divide by 0 -- it's impossible!
399 x 5
399 x 5 = 1995
Morah Lilia and Morah Halley have five days to write report cards for all 42 of their students. About how much time (hours) can they spend on each one?
Five days = 24 hours x 5 Two days = 120 hours
120 hours ÷ 42 students
Rounding --> 120 hours ÷ 40 students
120 ÷ 40 = 3
Morah Lilia and Morah Halley can spend about 3 hours on each report card.
915
x 82
-------
915
x 82
-------
75 030
493 ÷ 9
493 ÷ 9 = 54 r 7