Idea 11of 23Builds on13% sales tax
Estimate the tax and the change
How can you estimate the tax and your change in your head?
Today you'll discover
- why 15% is a friendly estimate of 13%
- how to find 15% quickly
- how to estimate the change
Think firstA $30 hoodie, 13% tax, paid with $50
You pay for the $30 hoodie with a $50 bill. About how much change?
Decide first, then press Next. Find one tenth first, then half of it.
A bar for a $30.00 price, cut into ten parts. The first part is shaded: 10% is $3.00. An enlarged strip shows half of that part shaded: 5% is $1.50. Then a longer bar: $30.00 plus about $4.50 of tax, about $35, and change from $50 of about $15. Then the exact version: $33.90, change $16.10. The last step asks about a $60 game paid with $100.
See the whole ideathe big idea and the key word, in one place
The big idea
Estimate 13% tax as 15%: one tenth plus half of a tenth. Then find the change.
Then check exactlyA calculator gives $30 + 13% = $33.90, so the change is $16.10. The estimate, about $15, was close and a little careful.
Easy to get wrongForgetting the tax makes the change look bigger than it will be. Expect to pay more than the shelf price.
Key word
- friendly percent
- a percent that is easy to work out in your head, like 10%, 5% or 15%, used to estimate
Ready to use it?
- Estimate 13% tax as 15%.
- Estimate the change, then check it exactly.