Grade 4 - Progress in Mathematics

Multiply mentally.

1. 18 2. 24 3. 57 4. 61 5. 50
   
   10
   10
   10
   10
   10


2. 345 7. 638 8. 999 9. 450 10. 690
   
   10
   10
   10
   10
   10

Patterns in Multiplication

4-10

Look for patterns to help you multiply by 10.

1 
 35  35 1 
 50  50 1 
 457  457

10 
 35  350 10 
 50  500 10 
 457  4570

10 
 350  3500 10 
 500  5000

Look for patterns or basic facts to help you multiply by tens.

8 
 40  320 9 
 31  279

80 
 40  3200 90 
 31  2790

80 
 400  32 ,000 90 
 310 27,9 00

To multiply a number by 10

or by tens:


Multiply the nonzero digits.


Count the number of zeros in the factors.

Then write the same number of zeros in the product.

35 500 457


 10 
 10 
 10

350 5000 4570

40 400 31 310


 80 
 80 
 90 
 90

3200 32, 000 2790 27,9 00

Hint

The number of zeros in the product

should be the same as the number

of zeros in boththe factors.

2 zeros

2 zeros

3 zeros

3 zeros

1 zero

1 zero

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