Mutiply and divide by 10/100/1000
Calculate: 45 x 10
What is 450?
Calculate: 10 + 5 x 2
What is 20? (Do 5 x 2 first!)
To solve 2 x 47 x 5 easily, you should multiply these two numbers first.
What are 2 and 5? (Because 2 x 5 = 10)
Calculate: 480 ÷ 8
What is 60? (Think 48 ÷ 8 = 6, then add the zero)
Calculate: 15 x 12
What is 180? (Tip: 15 x 10 = 150, plus 15 x 2 = 30)
Calculate: 6,700 ÷ 100
What is 67?
Calculate: 20 - 4 x 3
What is 8? (Do 4 x 3 first!)
Use regrouping to solve this quickly: 25 x 13 x 4
What is 1,300? (25 x 4 = 100, then 100 x 13)
Calculate: 734 ÷ 5. Give your answer with a remainder.
What is 146 r 4?
Calculate: 45 x 16
What is 720?
To move the decimal point from 0.82 to 82, you must multiply by this number.
What is 100?
Calculate: 15 ÷ 3 + 10
What is 15? (Do 15 ÷ 3 first!)
4 x 18 can be solved by doing (4 x 10) + (4 x 8). This is known as this "Law.
What is the Distributive Law?
A bakery makes 240 cupcakes and puts them into boxes of 6. How many boxes do they fill?
What is 40? (24 ÷ 6 = 4)
Calculate: 125 x 8
What is 1,000? (Tip: 125 x 4 = 500, then double it!)
Calculate: 45.9 ÷ 1000
What is 0.0459?
Calculate: 12 + 8 ÷ 2 - 3
What is 13? (Divide 8 by 2 first, then add and subtract!)
Use the Associative Law to solve this mentally: 2 x 47 x 50
What is 4,700? (2 x 50 = 100, then 100 x 47)
35 students are going on a trip. Each van holds 6 students. How many vans are needed so everyone has a seat?
What is 6? (35 ÷ 6 = 5 r 5, so you need an extra van for the 5 leftover students)
Calculate: 524 x 16
What is 8,384? (5,240 + 3,144)
Start with 3.2. Multiply it by 100, then divide the result by 10.
What is 32? (320 ÷ 10)
Calculate: 5 + 6 x 4 - 2
What is 27? (Multiply 6 x 4 first!)
Solve 8 x 15 using the "Doubling and Halving" strategy (e.g., 4 x 30).
What is 120?
Divide 100 by 3. Give your answer with a remainder.
What is 33 r 1?
Calculate: 638 x 14
What is 8,932? (6,380 + 2,552)