Mixed Math: Add & Subtract Money
š Red Light vs. Green Light (Money Edition!). Did you earn the money, or did you drop the money in a storm drain?
Concept
The ultimate test of fluency. You must read the sign and instantly switch the rules in your brain. šÆ **The Universal Money Rules:** 1. **Green Light (+):** Stack the dots! Start right. Make number bigger. Carry (+1) if 10 or more. Drop the dot! 2. **Red Light (-):** Stack the dots! Start right. Make number smaller. Knock next door & borrow if top number is stuck. Drop the dot! If you add a Subtraction problem, your money will be completely wrong.
Try it
Do not cross the streams! **Instructions:** Check the sign (+ or -). Pick the right universe of rules! Drop the dot! **Problem 1:** $0.65 + $0.28 ------- * Sign: PLUS! (Add them!). 5+8=13. Carry the 1. * Answer: $_.___ **Problem 2:** $0.81 - $0.34 ------- * Sign: MINUS! (Take away!). 4 is bigger than 1. Go next door to the 8! * Answer: $_.___ **Problem 3:** $0.40 - $0.25 ------- * Sign: MINUS! (0 is stuck! Go next door!). * Answer: $_.___ **Problem 4:** $0.50 + $0.50 ------- * Sign: PLUS! (0+0=0. 5+5=10. Write the whole 10!). * Answer: $_.___