In year 4 math, students learn to multiply numbers by 10 and 100. These concepts are important building blocks for understanding place value and larger numbers.
To multiply a number by 10, you simply add a zero to the end of the number. For example:
- 2 x 10 = 20
- 5 x 10 = 50
- 8 x 10 = 80
To multiply a number by 100, you add two zeros to the end of the number. For example:
- 2 x 100 = 200
- 5 x 100 = 500
- 8 x 100 = 800
It’s also important to note that when multiplying by 100 the number of zeros is the same as the number of digits in the number being multiplied.
Another way to think about it is that multiplying by 10 is like shifting the digits one place to the left and adding a zero, and multiplying by 100 is like shifting the digits two places to the left and adding two zeroes.
For example, to multiply 34 by 10, you can think of it as moving the digits one place to the left (3 tens and 4 ones) and adding a zero at the end, so 34 x 10 = 340. Similarly, to multiply 34 by 100, you can think of it as moving the digits two places to the left and adding two zeroes at the end, so 34 x 100 = 3400.
It’s important to practice these skills and be able to multiply numbers quickly and accurately. You can practice with worksheets or math games that focus on multiplying by 10 and 100.