Multiplication and Its Properties
Start at 0 on a number line. Make 7 jumps of 3 to the right. Where do you land?
21.
7 × 3 = 21
Calculate: 72 ÷ 6.
12.
Check: 12 × 6 = 72.
Calculate: 20 − 3 × 4.
8.
Multiply first: 20 − 12 = 8.
Which numbers are divisible by 5: 124, 250, 363, 415?
250 and 415.
Their last digit is 0 or 5.
There are 8 tables with 6 pupils at each table. How many pupils are there?
48 pupils.
8 × 6 = 48.
Calculate: 209 × 100.
20,900.
Each digit moves two places to the left.
Calculate: 0 ÷ 15.
Is 15 ÷ 0 defined?
0;
no. Division by zero is undefined.
Calculate: (45 + 15) ÷ 10.
6.
Calculate inside the brackets first: 60 ÷ 10.
Is 918 divisible by 9? Explain.
Yes.
9 + 1 + 8 = 18, which is divisible by 9.
Share 144 exercise books equally among 12 pupils. How many books does each pupil receive?
12 books.
144 ÷ 12 = 12.
Name both properties: 6 × 11 = 11 × 6, and
(2 × 7) × 5 = 2 × (7 × 5).
Commutative property;
associative property.
Divide 87 by 5. Give the quotient and remainder.
Quotient 17, remainder 2.
87 = 5 × 17 + 2.
Calculate: 84 ÷ 7 × 2 + 6.
30.
Work left to right for division and multiplication: 12 × 2 + 6.
List all positive factors of 32.
1, 2, 4, 8, 16, 32.
A school buys 15 packs of 20 sheets of coloured paper. Pupils use 86 sheets. How many sheets remain?
214 sheets.
15 × 20 − 86 = 300 − 86.
Find the missing number and calculate: 46 × ___ × 5 = 46 × 5.
1;
the product is 230. The identity element for multiplication is 1.
Complete the division algorithm: 194 = 9 × ___ + ___. The remainder must be less than 9.
194 = 9 × 21 + 5.
Find the sum: 1 + 2 + 3 + … + 25.
325.
Make 12 pairs of 26, then add the middle number: 12 × 26 + 13.
Find all common positive divisors of 28 and 42.
1, 2, 7, 14.
Pack 203 apples into boxes that hold 9 apples each. How many full boxes can you fill, and how many apples remain?
22 full boxes and 5 apples remaining.
203 = 9 × 22 + 5.
Use the distributive property to calculate: 37 × 99.
3,663.
37 × (100 − 1) = 3,700 − 37.
A number divided by 8 gives a quotient of 16 and a remainder of 7. What quotient and remainder do you get when the same number is divided by 9?
Quotient 15, remainder 0.
The number is 8 × 16 + 7 = 135, and 135 ÷ 9 = 15.
Find the sum: 18 + 19 + 20 + … + 42.
750.
k=b-a+1
s=k*(a+b)/2
Find every digit □ that makes 7□2 divisible by 6.
0, 3, 6 or 9.
The number is even. Its digit sum, 9 + □, must also be divisible by 3.
A school buys 24 boxes of 18 pencils. It shares all the pencils equally among 9 classes. Each class then gives 2 pencils to each of its 21 pupils. How many pencils remain in each class?
6 pencils per class.
24 × 18 = 432. Each class receives 432 ÷ 9 = 48 pencils and gives out 2 × 21 = 42. Then 48 − 42 = 6.