Multiplying 2-digit by 1-digit
Multiplication · Class IV
Watch the partial products line up.
24
type a value
1099
6
type a value
29
Live values
- Product144
- Tens part120
- Ones part24
- y = b*x (multiples of b)
Formulas in this lab
- Product
- Tens part
- Ones part
Tip: All multiples of b lie on a straight line through the origin , the slope is b.
Frequently asked questions
▶How do we multiply a 2-digit by a 1-digit number?
Break the 2-digit number into tens and ones. Multiply each by the 1-digit number, then add. For 23 times 4: 20 times 4 is 80, and 3 times 4 is 12. Add to get 92.
▶How do I use this multiplication lab?
Pick a 2-digit number and a 1-digit number with sliders. The lab shows the partial products lined up: tens part first, then ones part. The two are added to give the final answer.
▶When do we multiply like this?
If one packet of biscuits costs 35 rupees, then 4 packets cost 35 times 4, which is 140 rupees. Buying multiple items at a shop is a daily example.
▶Tip for partial products
Always multiply the ones first, write down, then the tens. Adding from the right keeps the columns lined up. Once you see the pattern, multiplying becomes quick mental work.