Multiplying by 10, 100, 1000 By the end of the lesson we will be able to: multiply any whole number by 10, 100, 1000 multiply any whole number by multiples of 10,100,1000
What happens when we multiply a number by 10? The value of each digit increases 10 times! When 46 is multiplied by 10, the 6 units becomes 6 tens and the 4 tens becomes 4 hundreds 46 × 10 = 460
7 x 10 Thousands Hundreds Tens Units 7
4 x 10 Thousands Hundreds Tens Units 4
38 x 10 Thousands Hundreds Tens Units 3 8
91 x 10 Thousands Hundreds Tens Units 1 9
268 x 10 Thousands Hundreds Tens Units 6 8 2
999 x 10 Thousands Hundreds Tens Units 9
What happens when we multiply a number by 100? The value of each digit increases 100 times! When 46 is multiplied by 100, the 6 units becomes 6 hundreds and the 4 tens becomes 4 thousands 46 × 100 = 4600
4 x 100 Thousands Hundreds Tens Units 4
82 x 100 Thousands Hundreds Tens Units 8 2
6 x 1000 Thousands Hundreds Tens Units 6
SHORTCUT Add one 0 Multiply by 10 Multiply by 100 Multiply by 1000 Add two 0’s Add three 0’s since 10 has one 0 since 100 has two 0’s since 1000 has three 0’s
42 × 300 Timmy thinks about how he can use what he knows about multiplying by 10,100,1000 to work this multiplication quickly 12600
Process 2. By 100? Add two zeros 3. By 1000? Add three zeros 1. By 10? Add one zero 2. By 100? Add two zeros 3. By 1000? Add three zeros 4. By a multiple of 10,100 or 1000? split up the multiplication, so that you multiply by 10, 100,1000 ex. 53 x 400 = 53 x 4 x 100
TASK (BINGO) Draw a 3 x 3 grid as shown below: 520 4730 47300 5200 3560 35600 946000 156000 356000 3500 1050 700 2100 35000 6270 21000 Place any nine numbers below into the grid (repeats forbidden) Who finishes a horizontal line first won the line Who finishes house first won the house 16
TASK (BINGO) What is 356 x 10? 3560 17
TASK (BINGO) What is 52 x 100? 5200 18
TASK (BINGO) What is 473 x 2000? 946000 19
TASK (BINGO) What is 52 x 10? 520 20
TASK (BINGO) What is 473 x 100? 47300 21
TASK (BINGO) What is 473 x 10? 4730 22
TASK (BINGO) What is 21 x 1000? 21000 23
TASK (BINGO) What is 356 x 100? 35600 24
TASK (BINGO) What is 35 x 20? 700 25
TASK (BINGO) What is 35 x 100? 3500 26
TASK (BINGO) What is 52 x 3000? 156000 27
TASK (BINGO) What is 356 x 1000? 356000 28
TASK (BINGO) What is 210 x 10? 2100 29
TASK (BINGO) What is 21 x 50? 1050 30
TASK (BINGO) What is 350 x 100? 35000 31
TASK (BINGO) What is 627 x 10? 6270 32
Multiplying by 10, 100, 1000 By the end of the lesson we will be able to: multiply any whole number by 10, 100, 1000 multiply any whole number by multiples of 10,100,1000
STP 7 Pg 20 Exercise 2b No. 1-6 and 32,33,34 Homework for MONDAY STP 7 Pg 20 Exercise 2b No. 1-6 and 32,33,34