A letter is a number you don't know yet. Undo what was done to it: for n + 27 = 63, take 27 from 63, so n = 36. Put it back in to check.
variablea letter that stands for a number
equationtwo sides that are equal, joined by =
expressionnumbers, letters and signs with no =
solvefind the number that makes it true
Watch for: Writing 7 − n for 7 less than a number (it's n − 7). Adding when the equation needs undoing: n − 12 = 30 gives n = 18. Not checking the answer in the equation.
At home: Play 'I'm thinking of a number': 'I add 9 and get 25.' Write it as n + 9 = 25 together, then solve.
Sample sheet and answer key
Luna's Space Adventure
Grade 5 · Letters for unknowns · 5.PFA.2
NameDate
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
A number minus 5 is 24.y + 5 = 24y − 5 = 24y ÷ 5 = 24
8 times a number is 72.8 ÷ y = 728 × y = 72y + 8 = 72
9 more than a number is 20.9 ÷ y = 20y + 9 = 20y ÷ 9 = 20
Write it, then solve it
Use n for the unknown. Write an equation, then find n.
Gia shares some cards equally among 3 friends. Each gets 12.n ÷ 3 = 12, n = 36
Hugo had some stickers, got 4 more, and now has 44.n + 4 = 44, n = 40
Answer key
Something wrong with this sheet? A wrong answer, a hard-to-read picture? Report it
New problems every time, three levels (gentle, core and stretch), themes to pick from, a second page if you want one. Each sheet comes with an answer key and a one-page guide for grown-ups.
