Add 129 to a multiple of 10
for 5th grade
Add 129 to a number by first adding 130 and then subtracting 1 from the result
Add 129 to a multiple of 10
When you add to a large number, you can use simple tricks to help you. This is especially so when the large number's unit value is a 9 or a 1.
When adding 129, it is often easier to first add 130, and then subtract 1.
For instance, if you wanted to do the sum 160 + 129:
160 + 129 = (160 + 130) - 1
290 - 1 = 289
Of course, this trick also works when the initial number is not a multiple of 10:
164 + 129 = (164 + 130) - 1 = 294 - 1
You can use a similar technique whenever the number to be added has a unit value of 9 - round that number up to nearest 10, do the addition then take 1 away. If you practice this technique using some of our timed games, you will soon get very good at doing this in your head in a very short time.
Below is a table showing the first 8 question answer pairs for the topic "Add 129 to a multiple of 10" as used in the lessons for this topic. Our games and tests for the topic use these 8 items plus 20 additional question answer pairs.
The topic "Add 129 to a multiple of 10" is in the category Add + Subtract for 5th grade (ages 10 to 11).
Revise 'Add 129 to a multiple of 10' with one of our games for 5th grade
Each of our math topics for elementary are made up of between 6 and 20 question and answer pairs (both the written form and a robot voice speaking those questions and answers). Each topic can be used with all the activities on the site.
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