🔢 Adding and Subtracting to 20

What you’ll learn

1. Speedy Small FactsAdd and subtract within 5 quickly, moving from counting to just knowing.Small facts like 2 + 3 = 5 and 5 − 2 = 3 can live in your memory. When you see small groups of dots, your brain can learn to know the total without counting. Practicing out loud at snack time makes the little facts pop out fast — and fast little facts make big math easier.
2. Adding to 20Add within 20, like 14 + 5 = 19, by keeping the big number and counting on.Teen numbers are a ten with extras riding along — 14 is 10 and 4. To add, keep the big number in your head and count on: for 14 + 5, say 15, 16, 17, 18, 19. Fingers can track your hops so you never lose count.
3. Subtracting Within 20Subtract within 20, like 17 − 3 = 14, by hopping back, and check answers by adding.To subtract, hop backwards from the big number — for 17 − 3, hop 16, 15, 14. Only hop the exact number you take away. Best of all, adding checks your work: 14 + 3 = 17, so 17 − 3 = 14 must be right!
4. Zero and Getting SpeedyAdd and subtract with zero, and choose the right strategy for problems up to 20.Zero is the nothing number. Adding or taking away zero changes nothing: 6 + 0 = 6 and 6 − 0 = 6. Taking away everything leaves zero: 4 − 4 = 0. With fast facts, counting on, hopping back, and zero tricks, you have a whole toolbox for math to 20.

Questions this course answers

Grounded in trusted sources

• PBS Kids — early math
• Khan Academy Kids
• NAEYC — early math learning
• Britannica Kids

Every Wunder lesson is built from real, reputable sources — never invented.

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