Mixed Practice: Addition & Subtraction to 20
π Sign Check! It's time to mix the pluses and minuses together! You have to be a careful detective so you don't do the wrong math.
Do this: Read the concept below, then try the quiz or activity.
Concept
You know how to add, and you know how to subtract. But when they are mixed up on the same page, your brain can get confused!
π― The #1 Rule of Mixed Math: LOOK AT THE SIGN FIRST. Before you even look at the numbers, look at the symbol in the middle. * Is it a + (Plus)? You are combining things to get a BIGGER number! * Is it a - (Minus)? You are taking things away to get a SMALLER number!
If your brain sees "4 _ 4", it might instantly shout "8!" But what if the sign was a minus? (4 - 4 = 0!). Always check the sign.
Try it
Don't get tricked! Check the signs!
Instructions: Look closely at the + or - sign before solving.
Round 1: Switcheroo 1. 10 + 5 = ___ 2. 10 - 5 = ___ 3. 8 + 8 = ___ 4. 16 - 8 = ___
Round 2: Brain Benders 5. 14 - 7 = ___ 6. 6 + 9 = ___ 7. 20 - 2 = ___ 8. 7 + 7 = ___
Round 3: Speed Check 9. 15 - 6 = ___ 10. 8 + 4 = ___ 11. 19 - 17 = ___ (Hint: They are close! Count up!) 12. 12 - 0 = ___