Which Sign Makes the Number Sentence True?
🕵️♂️ Oh no! Someone stole the math signs! You have to look at the numbers and the answer to figure out if it was a PLUS or a MINUS.
Do this: Read the concept below, then try the quiz or activity.
Concept
These puzzles are completely missing their operation signs (+ or -)! You have to be a detective to put them back.
🎯 The Size Trick: Look at the starting number and the answer. Example: 12 ___ 4 = 16 1. Start: 12. Answer: 16. 2. Did the number get BIGGER or SMALLER? 3. It got bigger! The only way to make a number bigger is to ADD (+). 4. Let's test it: 12 + 4 = 16. It works!
Example: 15 ___ 5 = 10 1. Start: 15. Answer: 10. 2. Did it get bigger or smaller? It got smaller! 3. The only way to make it smaller is to SUBTRACT (-). 4. Let's test it: 15 - 5 = 10. It works!
Try it
Find the missing signs!
Instructions: Did the number get bigger or smaller? Write a (+) or a (-) in the blank.
Problem 1: 14 ___ 5 = 19 * Did 14 turn into a bigger or smaller number? * Sign: ___
Problem 2: 18 ___ 6 = 12 * Sign: ___
Problem 3: 8 ___ 8 = 16 * Sign: ___
Problem 4: 11 ___ 2 = 9 * Sign: ___
Problem 5: 20 ___ 0 = 20 * (Trick question! Both 20+0 and 20-0 equal 20! So either sign is right!)
Problem 6: 7 ___ 5 = 12